PA5MW

ANY antenna beats NO antenna

2011-03-11T15:54:00.008+01:00

Stop modeling and get on the air; NOW.
After having moved, a couple of years ago, I wanted to launch my 160m activities at this new QTH. But the list of opportunities was quickly overtaken by the local challenges. The few attempts were marred either by public exposure (neighbors included), safety issues (see nov 1 2009)and lack of real estate. Next, work and other activities shifted priorities such that I kept stuck at the stage of computer aided antenna modeling.
I had to lower my ambitions as advancing plans to the next season again and again, did not get me anywhere and certainly not the pleasure of simply making QSO's on Topband.

The stealth Topband Antenna
An unobtrusive wire up in the air as high as possible, plus a few radials on the ground resembling some sort of basic Groundplane Antenna are my major goals.
I already tried getting different wires up a large tree, but the launching velocity power of my legal sling shot wasn't sufficient.
A friend offered help by supplying a special tinned copper wire having teflon isolation. At only 0.2mm diameter this stuff is both unobtrusive and extremely light.
With help of the slingshot it is quickly launched in a large tree using a 40g weight at the end.

It's the white wire, routed along branches of a small dead tree in the back garden. The horizontal wire is a short wideband horizontal antenna.
From here it goes upwards to a large tree some 15m away, ending at a height of >22m and then some length horizontal tangled up in the branches. In total I guess, about 26mtrs. Unimportant really, since there are plenty of opportunities to match it on 160m.

A copper ground rod and some 6 attached radials varying from 6 to 9mtr (20-30ft) in length are covering the west-to-northwest quadrant. Minor detail; since the vertical wire rises up in the southeast direction, none of these few radials cover the area under this sloped GP.
The white box is a True Balance type remote controlled ATU, which was not used for 7 years already. Together with some common mode supressor #31 FT240 ferrite core and already available coax from earlier experiments, I'm connected.

The final picture already shows the current situation where I have added another 10 radials in this small quadrant. The Yagi is my next priority for the summers Es season on 6m. And yes, that door in the upper right does need some maintenance attention.

So how does it play, QSO-wise?
Let's summarize this: a lossy 0.2mm dia wire, an even less-than-poor man's RF ground, a quick&dirty matching unit and 100W input power for that 'Sloped 160m GP'. Good points: it's at least 1/8 wave up and free in the air.
Within the hour I work stations on Topband within a 2000 km range including an UA2, but some later an Asian UA9.
The next morning at 05:54 UTC I work Dave, W5UN. Wow! Was that perhaps a special moment of extraordinary propagation? Later that evening I meet and work another well known Magic Band operator UK9AA. Two more US stations from PA and TX are worked in the next few days. It's no magic, using only 100W this antenna exceeds my expectations.
In between I have added some 10 more radials in by tiny 8x7m backyard. It requires a different setting on the remote ATU.
Using my short RX vertical I can hear many of the active dx'ers and dx-peditions on 160m. Most have large pile ups and are gone before I can make the contact. That is fully acceptable; this must not be too easy right?
New continents are entered in my log soon; JA7NI and today FM5CD. Both take some time before they are able to dig out my puny Little Pistol signal. Slow speed and perseverance while riding the QSB waves proves successfully.
Now how cool is this ???

What's next?
In the next weeks I will try to arrange:

Replace the ATU for a Low loss matching unit using a Heavy Duty Coil
Detune the TX antenna to lower (induced noise) coupling to my RX antennas
Add a PTT controlled RX antenna sequencing
Make more QSO's, have fun operating Topband

Back to Analog Basics

2010-09-19T12:26:00.035+02:00

Recognize this?

Your current digital product, appliance or service is offering you daily problems. You're fighting your way through settings via zillions of sub-sub-menus, hoping to get that one simple task done. In fact your 'life-style experience' thingy is a product of guaranteed instant stress.

Now there are always some geeks nearby, offering 'help' by friendly telling: you are doing it all wrong. Your settings are incorrect and additionally need to be tweaked(by principal), upgrades installed and special geek-tricks added to the equation before such a device can work at all... This takes time. Yes a lot of precious time (hours), during which you're told how you are living your life utterly wrong, explained at the same geek tech level, which slows down your present perception of (lost) time even more.

And then it shows; the offered intervention did not help.

Surprisingly this does not change the mood of your geek-friend. Quite the opposite; you receive an even longer explanation about why it did not work. In many details that is, until you finally surrender by nodding that you understand him completely...

Why these creatures are willing to spoil so many consecutive hours of what could have been a fine day is beyond my comprehension (I already exploded mentally twice). I know the world needs them for propelling our technical development. And basically, I am a technician as well. Professionally I'm creating bridges between Planet Geek and Earth, thereby understanding both entities. But in my free time I find myself more often in the base camp of the average John Doe nowadays. Effectively I'm pulling myself away from the interventions and want to call it a day. However my friend is more focused than ever and does not let go.

More geek tricks are pulled in and, since the challenge level is rising, others step in soon, turning this into a geek frenzy. After much longer it is finally your product bursting up in flames at which the whole pack is joy-ably agreeing it is you who choose the wrong Operating System in the first place.

Well I'm sorry, but back on earth I find it an insult if one imposes such a discussion to a consumer in the year 2010. I know consumers are indeed slowly mentally degrading, but geeks lack common sense. The product is just crap, period.

Daily Digital Crap Products

Getting to my current affairs; I have been trying some 5 different types/brands Digital Cordless Telephone sets these last couple of years and concluded it's crap.

Battery charging issues, never correct battery indicator, non-responsive number buttons, blinking lights, alarm messages on the display etc...

My favorite annoyance is the "missed call" message on the display. It took 18 (!) button pushes to clear that message from the display, every-time. Why is it that manufacturers aside from implementing a hundred ridiculous options, cannot create a selectable basic simple operating mode, offering nothing but making a call?

I have installed one complete set with 4 handsets at my parents house. Their world is different and they do not recognize any of the display messages at all. And the one in their bedroom is blinking red from day one. Every time a unit does not work or responds differently, they conclude it's probably their operating error and accept that. Hmmmm...... maybe a small learning opportunity for the control freak?

Back to Analog Basics

Out goes the digital crap phone stuff, in comes the Beocom 2000 from Bang & Olufsen. I bought this telephone sometime during 1990-1995. It has an astonishing design. It's greatest asset was and still is its superb audio quality. I used this great device for over 12 years without a flaw ever...

The brown leather pouf is over 35 years old and needed a 2 hour leather creme polish as it was totally dried out. Both are milestones from the past. Guess what? They both still function well.
This model has just a few basic functions like 20 memories, a red emergency number button, an LCD showing the dialed number (no call ID recognition) and 3 selectable true analog ring-tones.
Installation process takes 1 single non-dramatic step: connecting your RJ11 cable. No batteries to install and charge 24hrs, no firmware upgrade, no operating system settings, no help desk and no on-line manual.

That long greyish thing on the left is your handset(wired connection!). As soon as you pick it up from the hook-switch you hear the analog line buzz. Not that digital created artificial sound image from the past, just the real thing.
No answering machine, mailbox, Call ID and/or hide call ID. Just the basics needed for a phone conversation between earthlings.

Doing it right....

2010-02-24T16:44:00.016+01:00

ARRL DX CW Contest 20-21 feb 2010

Last weekend I participated at our club station PI4TUE.

This is the University of Technology Eindhoven's contest call.

Call: PI4TUE

Class: M/S HP

Operators: ON9CC, PC5A, PE2HD, PA5MW

Summary:
Band QSOs Mults
-------------------
160: 83 29
80: 261 42
40: 866 55
20: 999 59
15: 933 58
10:
-------------------
Total: 3142 243 Total Score = 2,290,518

Club affiliation: Bavarian Contest Club

Antennas: 160m sloper@220ft (RX: 5ft vertical@200ft), 80m full size horizontal
loop@220ft, 40m 1/4 GP @200ft, 20-10m 3el SteppIR
Rig: Ten-Tec ORION
Power: 400w from Acom 1000

Wow! This was big fun. Some of us love this contest even more than CQWW.
Finally we made some substantial progress compared to our past entries; at 1000 QSO's extra this year we have moved from the back end to the middle(ish). Watch out for us next year !

What went very well?

Preparation

This time I'm well prepared by taking a few days off before and after the contest. Being well rested and refraining from doing the *last minute job* I am fully motivated.

Looking fresh during the final hours...... :)))

Antennas
The new 3el SteppIR is a big improvement over the 15yrs old 3el compromise trapped(read: noisy) yagi. Next the 80m dipole at 220ft was replaced by a full size 80m horizontal loop at 200ft along the roof perimeter of the building (thanks to PA3DSC, PA0IB, PE2HD and PA3FGA).
But there is room for improvement for the RX antennas on 40-160m.

The HF2V mainly used for 40m

80m horizontal loop along the top perimeter. SteppIR 3el yagi. 160m sloper at the right end-corner

Rig
The ORION's user ergonomics offered its merits to all operators. Especially the setup for audio (main=both ears, sub RX =right only) and the volume knobs (toggle for audio on/off) was much appreciated for operating RUN/S&P between main and sub receiver with help of N1MM contesting software; Single Band SO2R in one box so to speak.

The station has no true SO2R capabilities. Another challenge for the future.

Second operator position....... not really.

Being focused
All operators were sharp from start till end. We strained for the best (band) strategy and our senior contest op successfully taught us additional tricks on the fly.

Operator Aurelio, PC5A looking sharp during sunday afternoon

Food, coffee, sleep, etc.
There was plenty of it all and the couches in the 'lounge' were comfortable for a quick nap.

What went not so well?

Pin 1 issues
We use some 5 pc's, various audio routing, external equipment and zillion connections for different set-ups in the shack. During the contest our headphones showed all kinds of strange varying noises, rattles and hum. The room houses another 30-40 pcs, several HF/VHF/UHF transceivers and other equipment. Definitely a challenge for the future.

Lockup/crashes
Very likely related to the above; WinKey locked up the N1MM program.

The ORION needed 4 power cycles (3 for no RX and 1 for no TX).

But
All in all a very memorable contest.
Thanks to Martin PA3DSC and Steef PA0IB for maintaining a great club station.

See you in the phone contest.
73 Mark, PA5MW

50 MHz Bandpass Filter from Cross Country Wireless (UK)

2010-02-20T11:02:00.009+01:00

Why a bandpass filter for 6m?
I recently ordered this from Cross Country Wireless and received this the other day.

There is a couple of reasons in no particular order:

Release any front-end(pre-amp) from strong out of band signals, thereby avoiding possible IM from local FM broadcast etc.
Avoid total blocking of 144Mhz while transmitting on 50Mhz

Both my transceiver, transverter and/or seperate pre-amp have internal bandpass filtering. The pre-amp even has a carefully tuned sharp helical filter. But in all cases the filtering is either very wideband or only after the LNA. A seperate, dedicated 6m bandpass filter might clear things up, in theory that is.

The Cross Country Wireless offers bandpass filters for 50, 70 and 144 Mhz. They handle 100W RF power and contain a built-in lightning surge arrestor as well. High voltage spike protection too; nice !

The bandpass filter comes with a filter test certificate, detailing RF and VSWR performance.

Final question: "will it result in more QSO's yes/no?"

Let's evaluate that in a few months.

For now I have to catch my next shift in the ARRL DX CW contest at our clubstation PI4TUE.
Have fun guys!

Cleaned up the measuring table/solder corner

2010-02-10T18:08:00.003+01:00

Cleaned out the soldering table

Installed two wooden shelves

Lined up the equipment at one side

Notice the army CW key?

Doing it wrong..

2010-02-02T22:46:00.000+01:00

CQWW 160m CW
My favourite contest.
These last few years I have hardly had time to participate seriously from anywhere.

Excuses, excuses
There's never been any time to prepare myself correctly (make that: I never took the opportunity..etc). Haven't built any decent station after my move to this new QTH. Not even the smallest 160m TX antenna. Not even a low dipole.
I do argue with others about which rig to buy or how to optimize for best performance on 160m, but have not made a single 160 QSO from this city lot yet. Go figure.
Last year there was this great QST article on the 160m No excuses homebrew vertical from John Miller, K6MM. I tried to build my version of a backyard vertical, but the neighbours strongly opposed to its physical exposure. And so it ended.

Even worse preparation for 2010
Now work goes before hobby and you better plan things ahead. Taking some days off is a good start. Arriving home at 01:15 AM after ploughing 150km through heavy snowfall, an earlier delayed flight, on a thursday morning and then try to catch-up the 'normal work' on the two left days of the week, is not a good start.
On saturday morning I awake early and monitor the progress of our club station PI4TUE in the CQWW 160m CW contest. They have a great TX antenna, using full size slopers from some 70mtrs(220ft) AGL. But they totally lack any RX antenna. Local environmental noise is such high that all past field experiments failed. It is frustrating to hear them miss all dx I can easily hear on my backyard small 160m RX reference vertical
I arrive at PI4TUE in the afternoon and take my shift from 15:00 till 18:00 UTC. After that I'm completely exhausted, cannot even stay to support the others and head home for a 12 hour sleep.
Sunday isn't any better so I go out for a 3 hour walk to catch some energy again.

3830 archives
Dink, N7WA offers a great service via the 3830 list and it's great fun to read the sopabox comments.
I'm flabbergasted by some of the low power/long wire entries; one European OM making 512 QSO's, 8 states and 52 countries using 5W and a 42mtr longwire ....

Lesson learned
Waiting & debating for the new & better station set-up can be an endless frustration.
Next time I will throw out some wire in a nearby tree, connect a tuner and use 100W, just for the weekend. And operate from my own shack, just having fun.
And have my own decent cappuccino

Ugh!

Upgrade the current VHF station IV; MDS measurement EXPLANATION

2009-12-30T17:41:00.037+01:00

General remarks
All rigs have been tested at 14 and 28.4Mhz and other adjacent frequencies to rule out bandfilter anomalies.
Pre-amps,RF gain, AGC and other possible settings which would affect the results have been optimised every time. During each measurement a verification was done with the reference K2 to rule out potential errors as much as possible. Many measurements, especially the hearing tests, were done by two persons.
The found ENB (Effective Noise Bandwidth, column H) allows for comparing apples to apples when talking filter bandwidth.
The filter curves were taken from the audio output using Spectrogram. The Elecraft Wide Band Noise Generator module was used to create a constant signal of about S2-S4.

Performance evaluation
Both column N and R are key in the evaluation of the measured results and hearing results on 144MHz.
Note:the measurement in column Q is totally different from the rest, where both the RF generator and transverter are using in- and outdoor-antennas:

As such there is a true radio spectrum in between as media. A real life performance test so to speak. Column Q represents the set RF output of the generator at which the MDS recognition threshold by human ear was found.
As mentioned before; I'm testing 28Mhz weak signal performance on a quiet band using a transverter, that is totally different from lowband and/or contest use

What really matters is about making that extra QSO yes/no.

Kenwood TS570SG
Frankly this rig was only tested during the preliminary test 'Method 1'; it is currently in use as an NCDXF HF beacon tracking receiver. The 570SG has the Inrad 400Hz CW filter and a temperature stabiliser for the LO crystal. Its internal DSP is an early 16 bit version; OK at 200Hz and above, but heavy ringing below.
28Mhz sensitivity is, next to the icom 7400, tops. However, for serious weak signal reception connected to a VHF transverter, this rig (and another 570DG) showed its weaknesses; the sound is rough, noisy and it just does not bring out the real weak ones. Is this due to its published high phase noise? Can't tell cause I have nothing to prove that. The

ICOM 746
This rig also has a 400Hz CW filter from Inrad. It's owner installed Individual Inrad filters for both IF stages, but previous experiences showed there is too much attenuation caused by bad internal gain distribution. Only the 400Hz in the 2nd IF was used as well as the original 2400Hz in the 3rd 455KHz IF stage. The additional AF CW peaking filters do work very well, but so does the free extra AF background noise. On 144 MHz its own internal VHF front end was used. In total it lacked some 5 dB in performance. When owning such a rig I would use an external preamp and bypass the internal.

ICOM 7400
The '746 Pro version' showed the best sensitivity on 28Mhz. Using its internal VHF front end, it does hold its own listening to carriers down in the noise (test method 1). But when trying to copy real CW signals the DSP offers a very rough sound and is ringing already from 200Hz and lower. I tried getting a better S/N result by adjusting its internal IF gain setting (input to the DSP unit), but apart from the gain difference in AF volume it did not offer any better result in the measurements, nor during the hearing results.

DSP filter curves at 300Hz and 200Hz settings
Please notice there 'brickstone' sharp shapes.
I have had another 7400 several years ago and used it intensively on 144MHz SSB and CW. The sound was very harsh and annoying over time. Then came the first K2 and a DEM 144/28 transverter; what a sonic relief!
Next, from the AB4OJ's Icom website I tried the following trick: choose a filter setting >500Hz and then reduce the bandwidth by offsetting the twin PBT controls. The final result is a 50Hz filter with a very bad shape factor, totally failing in selectivity but the sound is next to noisy much more mellow.

In practise this 50Hz 'low quality filter' offered the best results for the IC7400. Only feasible on a very quiet band. Maybe this will help me on my 50MHz set-up next season.

Microtelecom Perseus
This is not your typical rig where you turn the VFO knob and quickly use some dials & knobs to make a QSO. It is more a tool to monitor single frequencies or a whole frequency band and make that visual. But it does this very well. This high potential receiver has many capabilities (visual and audio) and has phase noise at such a low level(-140dBc @ 2KHz, -150dBc@10KHz), only seen at scientific equipment.
It offered the lowest measured result at 28MHz sensitivity. Due to its internal latency, a true S/N measurement using the Marconi analyser was not possible.
Interesting fact is that despite lacking 6dB at the bench test(column P), it does perform well during a real life hearing test, using an outdoor antenna (column Q). Might this be related to its extremely low phase noise?

Perseus at 416Hz and 202Hz settings

From this 141Hz setting and lower the ringing becomes worse; I mean ok for monitor carriers but incapable of decoding weak signal CW transmissions.

Elecraft K3 serial:173
We're in the upper class of this test now and the left differences are only minor. The K3 is third best at the bench test in column N. The final column R shows no result as the K3 was not available at that time. An 8-pole 400Hz roofing filter was installed. Interestingly, using the 250Hz roofer and tightening the DSP filter down from 250 to 50Hz the K3 showed a reverse result (worse S/N ratio) on the Marconi. Several actions have been tried: internal IF gain setting, AGC and finally switching from FIR to IIR at 100Hz and 50HZ. The final one was the only setting to show another single dB improvement, but the ringing is awful and makes a weak signal QSO impossible. The K3 starts with slight ringing from 150Hz and down. From there it becomes worse whatever the settings.

K3 400Hz and 200Hz FIR filters

K3 100Hz FIR and 100Hz IIR, please note that the IIR filter actually is wider.
This was also noted at the chapter FIR versus IIR filters at Clifton Laboratories.

50Hz FIR and 50Hz IIR; being a better 'peaking filter' the latter one did show minor improved measurement results.
Officially, any result difference within 3 dB should be considered "measurement deviations". But the differences are clearly there every day and remain when doing the test at a different QTH. When switching from the Marconi analyser to the hearing test, these last few dB's are still very apparent. Even more the perceived sound quality. This is where the K3 differs from the last 3 below; it sounds to harsh for weak signal. I have put out some questions on mailing lists and contacted different K3 owners; no special setting(s) for weak signal listening on VHF and up were found. Both the original K3 owner and another 6M enthusiast reported the same perceived 'harshness' compared to what they are used to at analogue rigs.
I'm not satisfied yet and convinced that we were not able, to let the K3 show its full merits here. Based on its published specs and current results at major HF contest stations, I trust the K3 will be a killer during 6m/VHF contests. Elecraft is continuously offering substantial firmware upgrades and the K3 shows increasing potential. I still fancy one..

Elecraft K2 serial:3323 original
This is a B version. It is a K2 in original shape and aligned according the written procedure. The internal crystal filters have been set-up for 1000, 700, 400 and 200Hz bandwidth.
It also has the additional KAF2 audio peaking filter (270Hz and 100Hz). This reduces the out of band noise:

The second picture shows the wideband performance curve using both the 200Hz crystal filter as well as the AF2 100Hz audio filter switched in. Unfortunately this AF2 100Hz filter introduces slight audible ringing.

The measured reduced sensitivity at 28MHz compared to 14Mhz is a normal behaviour.
The K2 does have a relatively low phase noise but at 7Mhz. But like most contenders, not particular that good at higher frequencies like 28Mhz. Nevertheless its performance is superb; hey we're in analogue heaven now! The noise-free AF section of the K2 makes the volume control even act like an additional RF gain. The sound is sweet and offers plenty of details in the quiet background.

Ten-Tec ORION
I have often used this rig for performance comparisons during the last 4 years and it has always been a close draw with the finalist below. The ORION had been modified by exchanging the 1000Hz crystal (roofing)filter for an Inrad 4-pole 600Hz. This special filter #762 was initiated on request of Bill Tippet, W4ZV as the original 500 and 300Hz filter upgrades created a worse IMD spec due to a distributed gain issue. This was solved in the later ORION II model.
During the sensitivity measurements it became very apparent that any RF gain setting above 92 was creating extra noise and upsetting the S/N measurement. I believe this is the reason why so many new users confirm so called noisy receiver behaviour. Setting the RF gain to an appropriate level is outside the general consumer perception. The manual does explain proper use of the RF gain, but for weak signal you are used to "dialing it up to the max". Thus I got results which are several dB's better than published elsewhere. But the verdict is in the hearing tests and the perceived audio performance. The ORION does very well in this area, being the best DSP rig in the test.

The above 200Hz and 100Hz DSP filter settings are 227Hz and 155Hz in reality.
Both filter curves represent a more analogue shape. Not the slightest ringing noted. Even the 100Hz DSP filter sounds as clean as possible. Perhaps this is due to different chosen DSP filter algorithms by Ten-Tec designers. It does offer the most analogue sound and shows great receiving performance; signals could still be detected deep down in its calm noise floor. What a relief for your ears.
Do not forget the PLL design offers an extremely low close-in phase noise, not matched by any other but the Perseus.
So far the ORION has offered me the best overall results in 22 years of Hamradio.

Elecraft K2 serial:2036 modified
In terms of options it is similar to the other K2. Several small upgrades have been done for boosting general performance. However the following modifications have been done over the years for optimisation on 28Mhz transverter use:

1. Pre-amp and AGC
The original preamp is a compromise in terms of system noise figure vs IMD performance. Changing its gain boosts its total system noise figure. More preamp gain involves a lower intercept point however.
See the Elecraft application note

2. 28MHz Band Filter
This is now peaked at 28.2 MHz

3. AF filter
The AF2 filter is changed from 100 to 140Hz. This small change reduces ringing completely.
The audio gain was slightly optimised by changing R9 to 12K.
Spectran was used to do the adjustment on the KAF2 board, which now peaked a few dB higher.

400Hz crystal +270 Hz audio filter. And 200Hz crystal +140Hz audio filter.

This modified K2 has proven its superiority during these tests. It also functioned as the reference rig during the tests. Switching back from any set-up to this little analogue wonder always immediately showed its advantage.

The verdict
Best reception: modified K2
Best overall performer: ORION
Best alternative 'second receiver': Perseus (visual performance)
Great future potential: K3

Analogue beats digital, but only just.
Razor sharp DSP filters offer bad audio for VHF weak signal CW message detection.
K2 and ORION offer sonic details like you are diving into the abyss of the RF noise floor.
What is the true 'supporting performance' of low phase noise?

Mission completed?
I wanted to measure the noise figure of my K2 and, in the process decided to do some more testing..
Got a bit carried away.... But then again, I never got to measure known VHF performers like the TS850, FT1000MP etc.. And then there's that superb Javornik transverter. And Down East Microwave is (re-)designing a new transverter.
Oh well... lot's of promises for the future ;)

Wish you all a Happy New Year !!!

73 Mark, PA5MW

Upgrade the current VHF station III; MDS measurement

2009-12-24T22:37:00.013+01:00

This follows the previous blogs on optimizing my Elecraft XV144 144/28MHz transverter + 28MHz IF transceiver

Purpose of MDS measurement
Find factual differences in 28MHz sensitivity of HF transceivers, using measuring equipment as well as ones own ears. Create repeatable and, as much as possible, reliable results.

Final decision criterion: Can I make that extra QSO Y/N ?

Prerequisites
Since my goal is to evaluate my local possible transverter+HF combo's, the actual measurements must reflect real life situations. There is plenty of good data available from ARRL, Sherwood, G3SJX etc.. But I need factual data on 28MHz. Every rig will be set-up for transverter use. If that is via other antenna entries, using extra relay routing, different internal circuitry etc... so be it. Every rig will be fine tuned for best performance on weak signal detection; being able to copy and read CW transmissions. That rules out filter settings which create ringing.

Getting a feel for measuring MDS
I have limited experience in doing this, I follow a different protocol and my equipment calibrations are outdated (2003). Below data is not scientific proof whatsoever. Nevertheless I have done my best to do make sure to deliver repeatable results. I tried a few different methods of determining MDS, just to get a feel and, more important, see how it relates to reality.

Test set-up

Headphones: David Clark Model 10/DC Stereo, with passive noise cancelling.
Picture shows a temporally test setup at a friends place.
The 'wires in the garden' is a K9AY low band receiving antenna.

Determining the MDS threshold reference level; method 1
This was determined by human ear recognition only:
Output RF generator: continuous carrier signal fixed set at -100dBm on 28.4 MHz and 144.4 MHz. It is capable of reducing its output down to -140dBm, but to rule out internal deviations and external possible load differences I used the step attenuator. A second identical step attenuator from a different brand was used from time to time for comparison and verification.
Generator connected via step attenuator to the 'Device Under Test', or to the Elecraft XV144 transverter, which in turn was connected to the DUT.
Output receiver: connected to headphones
Using the 10dB and 1dB switches of the step attenuator, a minimum threshold was found at which the RF signal can just be recognized and while turning the VFO the varying beat note can still be heard. This method delivers a more accurate and detectable threshold vs just a faint phantom signal xx dB buried in the noise.

The penultimate column shows the single receiver performance at 28.4MHz, the final column refers to the transverter combo result. Found 28MHz MDS values showed an average delta of 8dB compared to official published data which is 'promising'.

Determining the MDS threshold reference level; method 2
Taking it one step further I started doing the S/N measurement function on the Marconi communication analyser.

The second drawing shows the set-up with the 144/28 transverter 'combo'.
In both set-ups the audio is routed back to the analyser which determines the S/N figure.
At first I have done all tests using a 20dB S/N level as measuring reference, but since that is not resembling a true weak signal I cut it back to 10dB S/N. At that level all signals are already very near the noise level.
This test method quickly showed reliable results. I have repeated all measurements a minimum of 5 times at different days. To be sure I got the same repeatable results, each time the modded K2 was used as measuring reference. I spent 3 weeks doing this almost every evening. There was one occasion where all test results shifted 1dB on a single day only. But apart from that everything stayed rock solid. I got enthusiastic and started dragging in other rigs as well.

So what do we have here?
Column D: extras which do not come standard with the product
Column E: selected crystal filter in the 1st IF being the standard or an optional filter
Column F: set DSP filter. IIR and PBT refer to receiver custom settings
Column G: set audio 'peaking' filter, only applicable for K2 and the IC746
Column H: measured Effective Noise Bandwidth using info from Owen at: http://vk1od.net/measurement/enb/MeasureIfBw.htm
Column I: calculated using the metric converter at http://vk1od.net/calc/RxSensitivityCalc.htm
Column J: published MDS results from ARRL at 14 MHz (for comparison only)
Column K: measured S/N using the Marconi generator/analyser at the 10dB S/N level reference
Column L: same
Column M: same but now using the 144/28 transverter combo
Column N: calculated delta on results found in column M
Column O: same as K but using human ear for MDS recognition
Column P: same as O but using the 144/28 transverter combo
Column Q: same as column P but now the RF generator is connected to a small antenna loop and the transverter is connected to the outdoors 144 MHz yagi. The results shows the delta to the found "best in class" receiver.
Column R: remarks will be discussed in detail in the next blog.

"I'm not happy with your results....."
What does this all mean? Why is X doing this and Y doing that? My Z-rig at home does better than your measured yours etc.......
Please note the whole measurement concentrates on reading the signal at 28MHz under weak signal circumstances.
That is a zillion light years away from performance during a contest, let alone on low bands.
The hearing measurements were done with two persons and done as serious as possible. It even turned out my friend was able to dig another dB or two in the noise but he created an extremely small brain filter which was already pre-synced on the signal :). Fun but not the agreed threshold level where we could both detect and read the CW transmission.

So ????????
Benchmark results are nice for comparison and I'm pleased with the found noise figure results.
This will allow me to do careful calculations using the mentioned VK3UM application, see my earlier blog.

I appreciate the MDS test results 'by human ear' the most.
In the end the QSO is made using that exact instrument, so by upgrading my whole 144Mhz set-up I want to use that 'measurement tool' as much as possible. I'm very reluctant it turned out to be a reliable tool.
The S/N test function on the Marconi generator produces a modulated signal which sounds like separated dots (e-e-e-e-e) at some 15WPM. That is the close enough to reality and certainly much better than any stable continuous carrier.

During the tests there were large differences in sound quality perceived. DSP filters sometimes sounded harsh and extremely small filters introduced ringing. Ringing does not need to be a problem if there is plenty of signal, or you need to filter out the adjacent station during contest etc. However at the weak signal level on a quiet band ringing is not making that extra QSO.

Conclusion
The modded K2 sounded best and proved the winner for decoding weak signals, followed closely by the Orion and K3. The Perseus not only shows a great picture but offers good readability too.

What's next?
In the next blog I will comment on all tested receivers individually and explain in detail how they were set up and modified for best results. Their measured filter responses will be shown as well.

Upgrade current VHF station II; the plan

2009-12-02T13:25:00.012+01:00

What is my goal?
Pure and simple: have more fun in hearing (seeing?) weak signals, participate in a few contests and/or work new dx, on 144MHz.

Throw in some new hardware !!??
Now there's a lot you can do to upgrade your VHF station boosting the performance in theory, like:

- adding a pre-amp
- additional (band-)filtering
- mount the transverter near the antenna
- install extreme low-loss coax
- raising the antenna height
- buy new high performance equipment with DSP, add SDR receiver etc.
- low noise power supply

However, none of these will offer gain by principle.
All the above need to be seriously evaluated before implementation.

Hardware performance simulation
I do like VK3UM's EME system performance calculator a lot.
This great application allows you to evaluate your set-up and simulate any future upgrades.
See free software at: http://www.vk3bez.org/vk3um_software.htm

A typical view shot looks like this:

Mind you: there is RX Noise Figure which is determined by hardware only. And there is System Noise Temp and Noise Figure, which show the real life situation when terrestrial or sky noise is added to the equasion.

The hardware setup is clearly cut into pieces:
Antenna
Coax to the 1st RF stage (LNA)
Coax the the second RF stage (receiver)
Settings for coax type, connector and relay contact losses.

The program calculates both a total receiver noise figure based on pure hardware only, and a total system noise figure/noise temp, based on the environmental terrestrial sky noise (not EME).
Toggling the LNA on/off switch the total system noise figure gains 3dB at receiver performance.

The plan
Let's start evaluating the current total receiving performance.
There's only 2 building blocks in VK3UM's performance calculator. So I need to cut my 144MHz receiver chain in separate parts and evaluate the individual blocks first, before starting to calculate the total system performance.

my current blocks:

1. Antenna (Tonna 17el @12m AGL)
2. Coax into shack (2 pieces of EcoFlex-10 and -15 +5 connectors)
3. 144/28MHz transverter (Elecraft XV144)
4. 28MHz IF transceiver (Elecraft K2, modified for bettter 28MHz performance)

First step: evaluate transverter +IF receiver performance

I will need to do a MDS test on the K2 IF receiver

Upgrade current VHF station

2009-11-11T16:21:00.009+01:00

Planned changes

There's a few reasons why I'm planning some upgrades on my current VHF station. First there's the annual wear and tear; the 17el 6.67m 144MHz Tonna yagi has a bended boom, due to a storm last spring. The coax is some 5 years old and has a few connectors too many along the path. I want to raise that antenna to the max level officially allowed, which will involve another 1mtr above street level. There's an older 4el vertical yagi for long distance 145 FM repeaters for which I have a replacement 5 el version ready. The 70cm vertical omni and yagi combo is still awaiting going into service. And them some more minor things.
Then there's plenty of equipment in the shack which needs to be sorted out, optimised for performance and operation.

Check current beacons
Just for fun let's check two popular beacons.
Now this surely is very subjective since there are so many criteria involved which change from day to day. The weather today is cold, cloudy and moist. The FM repeater at 100km distance is a few dB down and shows some more noise on its signal than what is normal.
Waiting for the right up-swing in the very slow fading (several minutes to be exactly) I copy:

DB0FAI (A1A) on 144.490 from JN58IC
This German beacon uses a 16 el yagi mounted to a cows barn and puts out 100W pointed into my direction. Distance is 545km.
You can find more info on http://www.qsl.net/db0fai/

The displayed frequency shows the 28MHz IF ouput of the transverter plus its LO offset.
The beacon is at times pretty loud; some 34dB above the average noise level.

HB9HB (F1A) on 144.448 from JN37QF
This Swiss beacon puts out 10W into a 2el yagi also into my direction. Distance is 507km.
The location is on a mountain at 1395m ASL.
Details can be found at: http://www.hb9hb.ch
The F1A transmission effectively shows 2 signals after detection in CW mode with a 1 KHz difference. The signal on 448 sounds inverted, the one on 449 is normal. This makes finding HB9HB, which is always very weak at my place, both challenging and a good performance test for the receiving equipment.

Used equipment:

- Bended 17 el Tonna Yagi @ 12m ASL
- 25m Ecoflex 15 + 9m Ecoflex 10 coaxial cables
- Elecraft XV144 transverter (28Mhz output)
- home made 3dB splitter
- Modified Elecraft K2, optimised for 28Mhz
- Perseus SDR receiver

I'm using both the Perseus SDR as well as the Elecraft K2 for listening. The Perseus offers valuable virtual data, the K2 is the slightly better receiver. The 3dB splitter has no negative effect as there is plenty of signal from the transverter output.

The MPV project II

2009-11-01T17:04:00.011+01:00

The MPV rises to 16mtrs !
I have found a top section of an old 12m spiderpole. This came from a damaged Heavy Duty version and has served as an 160m vertical during a HB0 dx-pedition. However, despite wall thickness up to 2mm it didn't last long in high winds.

The 12m fibreglass pole can be spotted on top of a 20m alum mast which serves domestic logistics.

I allocated the top sections in the back of my shed and found them in good shape. A total length of 6.40m is available and it fits tight on the top section (22mm dia/2.5mm wall) of the earlier installed 10m DJ6NI mast. For the experiment I added a couple of hundred windings using 0.85mm lacquered copper clad steel wire from www.dxwire.de

Nice job done, but a quick check with my antenna analyser using some ground radials and a 3m ground rod, shows resonance at 1570KHz. And I haven't even hoisted up the bottom 10m sections. A few too many windings I say!
With the 40cm overlap and true snug fit the Most Pitiful Vertical is now at 16m.

But..............
I run upstairs in order to make a nice 'total view picture' from the 1st floor.
Looking outside I quickly recognize the downside of this kind of structures; wind.
Even the slightest afternoon breeze bends it like this:

Another guying point at the 10m point, just below the black top section, is not feasible. My guying locations are way too close and there's no room for attachment points farther away. Let alone the risk of tangled up guying wire during the daily job of sliding the whole structure in and out. BUMMER.

OK, where are we now?

This current 16m version is not an option.
Guess that a max of 12m vertical is possible, provided I use a thin wall fishing pole and no extra windings on the top section to minimize the load.
Explore option of a T-version, where the top-hat functions as guying. Max 12-14m height?
Better install an electrical 30m Bigh Bertha, which needs no guying and is 3m high (and the same amount buried in the ground with several tons of concrete, right?).

What went well?

Back yard has been cleaned up
Found that chicken mesh-wire functioning as ground screen is a realistic option

Only few weeks till CQ-WW CW

The MPV project

2009-10-21T13:09:00.006+02:00

"Most Pitiful Vertical"

It's time to become active on Top Band again!
Since the move to my new QTH there have been several options investigated on how to implement a vertical antenna for 160m. Discussions, software antenna models, wild ideas etc.. all with no result yet.
A recent article in QST described a "No excuses" home brew vertical by John K6MM. This helically wound vertical is only 25ft(7.6m) high, see details at his website
Sure, delivering a puny little signal this is no pileup-killer. But you make qso's and at right times you work some dx as well.
So why keep dreaming about that larger, but still compromise antenna in the woods behind the house, which by today remains not feasible and due to practical restrictions will still be a compromise?
Then there's this remote farm site available for serious 160m operation, but that's more than an hour drive from here. You want to check Top Band when you pee at nights right?. Maybe I can have fun even with a ridiculous small antenna.

On october 14th there was a cool presentation during a joint webinar from PVRC-NCCC by K6MM.

The MPV idea
Let's put up a vertical and see what I can accomplish. I sure can use the experience for future field operations. There is and have been so many reasons in the past to not put up a small vertical for 1.8MHz, both at home and on field locations.
As my garden measures only 8x7mtrs (600sq feet) there is another requirement: the vertical must be unobtrusive for the neighbourhood during daylight hours. This means I need to be able to take it down to a max 3m(10ft) level in a matter of minutes.

First steps
From DJ6NI I have the 10m version fibre-glass mast for more than 10 years now. It has served me on many occasions as mast for antennas like Inverted Vee, Vertical, K9AY etc. This very tough material and can carry a lot of weight. Each section can be locked and has a micro adjustment.
Why not install a 12, 18 or even the new 26m Spiderpole fishing rod? I have seen that big sucker at the Friedrichshafen Ham-Fair, but the 15 segments become quickly too heavy to lift. It's ok for any field day occasion, but not the daily install I have planned in my backyard. Not to mention it costs 549 euro.

Result
10m heavy duty mast. Can be set up within 2 minutes at minimal effort.
The top section is 22mm dia so there's opportunity for additional length.
Guying is done at the 6m level, using 2mm dynema.

No; for several reasons there is no possibility for a vertical in those trees behind.

Next

Find an extension like old fishing rod
Explore option for possible inverted L
Or helical windings
Create ground screen
Find the final resonance and add a tuning network at the bottom

I need to clean up the garden first.

2009-10-18T21:32:00.003+02:00

Goal for 2009 season
Like every year I do set reasonable goals for the 6m season. Yes; 'season' because outside the Es-propagation window of may-august, there's nothing to do on the 'Magic Band'. We are simply missing sunspots. Next, the targets must meet motivation, hardware and finally time with respect to work&daily social life (what?).

Do some research and implement changes
Find improvements
Competition; participate in annual marathon contest UKSMG
Work new countries
Fun factor; radio is a hobby. Wikipedia says:"Hobbies are practiced for interest and enjoyment". Playing with radio does serve both for me.

Things which worked well

Do some research, implement changes
Hardware; transceiver.
I have spent (too?)much time getting the most out of my 6m transceiver and/or finding a better rig. See my previous blog.
Hardware; antenna.
The main key factor at your station. Get more and bigger antennas up, right? However, measuring environmental noise hat put things into perspective. See my blog of April 12th.
Software; DxBase 2006 Logbook
I run two different logbooks on 6m; one all time logbook for entering any qso which is an all-time new country. Next I have the 2009 logbook which starts from scratch for the annual marathon UKSMG contest.
Software; re-calculating current station design.
VK3UM's Receiving Performance Calculator shows you the overall impact of changing the antenna, adding a pre-amp and/or installing low-loss coax. The total system noise temperature (or equivalent noise figure) shows how much can be really gained, or not. Set Sky noise at 5500 K, representing the average terrestrial noise in a city environment. Terrific software !

Find improvements
The Elecraft K2 +XV50 6m transverter has shown its merits on sensitivity and pure analogue sound quality. Ergonomically it proved not capable, yet.
The Perseus SDR receiver I have for some months now, shows great potential at several disciplines. Best in class performance at band monitoring, doing measurements, finding weak signals, next to being simply a superb DC to 35MHz receiver. Enjoying 22 years in Hamradio groundbreaking improvements have been: TS850, K2, ORION and the Perseus.
Reading the latest articles of YU1AW on principles of gain/temperature and 30 years development in yagi design, gives you new insights on terrestrial vs local man-made noise as well as relevant interpretation of the current new antenna designs.
I believe there is still room for improvement in my current 50 MHz station set-up.

Competition
Many european 6m operators participate in annual marathon contests. I'm publishing my efforts in the annual table of the UK Six Meter Group. The goal is trying to work as many countries in a single season. All modes are allowed. That is a lot of fun since you can start from scratch every new season. This creates an exciting alternative during these years of low sunspots and ample cross continent dx possibilities. I even run a seperate logbook for the this annual contest marathon. Having already 53 different DXCC countries in Europe makes this a tough task too. At least some 30 countries rely on short-skip propagation which occurs in very few occasions. It does sharpen your tools for hunting the real dx. On one hand this creates band activity, on the other you need to be careful avoiding 'QRM' since you are calling known & easy dx every year again and again. Example; when LY2xx finally becomes available I refrain from calling him immediately in the pile-up on his QRG. There's lots of stations who have never worked an LY ever, and maybe he just has a short window on a path to some other dx. I prefer to work him on a more quiet moment or when the band is just opening.
Achieving serious results requires serious dedication as some countries are available only very occasionally during the season. Sharing your experiences on-air or on the ON4KST webchat is fun.
My result for 2009: 78 worked DXCC countries. That puts me right in the top-ten ;-). Last year I managed 57, but then my QTH was home to a lovely YL (a matter of setting priorities so to speak). My annual record is 82 which happened in 2006. Getting to serious results is a matter of being there at the right time. My station has a single 5 el yagi @12mtrs AGL and output 100W (no PA available). I'm very satisfied with the results.

Mind you; although all modes are allowed in this marathon contest, I refuse any 'digital' modes and prefer only contacts which are truly by human only (own ears, voice and Bencher key).

Work new countries
Triple efforts are put into working a new country. The Es season showed many openings to the Caribic; on several evenings KP4's where available for many hours and could be worked on a rubber duck. New DXCC for me: Americas: VO, 8R, J3, J7, 9Y, from Africa: D4, 6W, TR, TN, 5N, from Asia: 4J, and from Europe: 3A. That makes 12 all time new ones.

Fun factor
Being this a hobby, not an obsession, one has to careful balance time&effort.
I enjoyed the many fine dx qso's made and also love to listen to fellow hams who made it through and share the excitement on the ON4KST chat. On some occasions it was nice to monitor the efforts of other, larger stations who challenge the 'Magic' properties of the 6m band.

Things which worked not so well

Hardware
Super low noise/high gain antennas only show their merits at the right QTH. An experiment using our HB0-dx antenna, seemed crippled due to lack of height and local noise. It was fun though to set it up, see blog of May 27th.
I also tried an experimental 1.5 wavelength inverted vee antenna at 5mtr AGL. This 50 Ohm antenna has 4 main lobes and served as second antenna. It did not offer anything valuable and was merely deaf in any direction.
The President Madison CB receiver, see my blog of July 11th, served as an experimental Es monitor/warning system. Monitored Es conditions on 27MHz are very different from 50MHz. More important; there is very little activity on CB except for Italy and France.

Band tourists, QRM etc..
Todays bad habit of "I want it all, I want it right now and at no effort" is affecting our ham radio bands for a long time. DX- clusters and Internet has made it worse. There are many hams with bad operating behavior and ditto QRO signals. They drop in upon a cluster spot and act like Monster Trucks, very often not even understanding what is actually going on on frequency and just repeatedly calling with the howling pack. Since the marginal band openings to real dx are such short and fragile, patience and optimal operating practice is most valuable. For everyone.
I have had to let go several potential new ones. Some ops do not understand the mechanism of shifting footprints during small openings and ruin opportunities for their neighbors. A pity, but new opportunities will arrive in the future.
The dx cluster nowadays has become a chatbox. Some digital 'QSO's even require 6 consecutive lines in the cluster to make it happen. Without any shame about the QRM or the bogus contact. Now try to reason them on a webchat.... If they would just care to enter their 'spots'on 50000.0 then it would be possible for us to filter it out.

Plans for 2010 season

TRX Hardware:
I will implement a second receiver setup; the XV50 transverter into a splitter(see blog march 26th), feeding both the K2 and the Perseus. A second smaller 6m yagi to monitor other directions will rise...somewhere...? This and the main antenna will be connected via a cross-switch antenna relay to both main and second transceiver set-up.

Software:
DXBase is aging and not being supported anymore. I want to try something new. I must be perfect to support logging for Top Band as well as VHF (6 & 2m) with plenty analysis options and monitoring alarming systems. Anyone have a good proposition, drop me a message please ?

Antenna:
I will do another local noise measurement, and thentry to raise my antenna a few meters.
Perhaps I will try the all new design from G0KSC.

Remote setup:
We have a farmers house available which is at a very quiet and remote location. Good opportunity for entering a 50 MHz contest.

Competition:
If time allows it; enter the annual marathon from http://6m.dy.fi/
Perhaps participate in a 6m contest.

So................
Okay that is way enough Magic band talk for now.
The 160m season has already started for crying out loud !
Time to move on.
Thanks and see you next season.

Getting the most out of your rig; the results after another 6m season

2009-09-13T16:35:00.024+02:00

Are we satisfied yet?
Another 50Mhz Es-season has just ended and I have (again) tried several transceiver set-ups and performed modifications on my 6m HF rig. From simple upgrades to a total change of the building blocks inside my rig. All just to achieve the maximum fun factor; which is combining the best possible ergonomics with optimal HF performance. Again, this is for 6m use only .
There have been a lot of opportunities to test all different equipment and many DX QSO's have been made on 6m during marginal conditions..

Why again am I so critical about the transceiver?
Working that dx on 50MHz is just a matter of being there at the exact right moment. And depending on your antenna & QTH those openings can be from several minutes down to just a few short peak moments, especially when your QTH suffers from local noise (see my blog from april 12th). Quick operating and an informative user interface are key here.
Sure you can make nice dx contacts with any rig on 6m. But from some years of experience, both at home and our summer dx location (HB0), I learned that some really can make a difference. At home I have a 5 element yagi @12m AGL and using 100W I managed to work >75 different countries during this summer Es season. Some were easy, others not. But the fun is in the game of the hunt right ?
Well sharpening your tools is too.

50MHz transceivers I have tested at home
Where did I end up last year?
My TS570SG received several upgrades including both 400 and 2100Hz IF crystal filters from INRAD, a temperature controlled crystal heater for the master LO and an outboard preamp from SSB Electronics.
In the end an IC746 on loan was much more fun and proved to be the master of ergonomics.

This year I tried some more HF rigs for 6m:
(note: these are my personal experiences. Please do not feel offended by my comments)

Kenwood TS570SG stage II upgrade
The whole internals of the rig have been changed through bypassing lots of circuitry like the bandfilter, attenuator, pre-amp and the complete front end stage, straight up till the 1st mixer input. See my previous blog. It was written some months after that modification was done so there was plenty of time to test and verify the results. RX is much better but the aged 16 bit AF DSP shows its limits.
Verdict: Filter settings less than 200Hz filtering are useless due to ringing. Ergonomically this rig is OK but it sure is not an IC746.

Elecraft K2+XV50 transverter
The Analogue Reference Combo, period.
What a sound, superb RX performance. Best building kit ever in history of Hamradio offering a great deal of satisfaction. And still lots of room for personal tweaking, upgrading etc.
Verdict: Ergonomics and quick 6m operation suck big time. Like every transverter the power is only 20W, thus requires an external amplifier.

K2+XV50 +HamRadio Deluxe
Been there, tried that using a Griffon USB PowerMate as VFO knob.
Verdict: slow tuning, no progressive speed like Icom, no real VFO feel, user interface not optimal.

K2+XV50 in Master-Slave link to the TS570SG.
Using the TS570 ergonomics to tune the VFO and link the K2. This set-up even allowed for RX diversity to some extent. Dedicated software written by a friend of a friend, see my blog on april the 9th.
Verdict: K2 has drift which needs to be re-set at every start-up. Early sw version has some bugs causing laptop hang-ups and small but evident latency. There sure is room for enhancement but I never gave it a real chance because a new opportunity arrived:

Icom IC7400 (=IC746 Pro)
Suddenly there is a used IC7400 available, in mint condition and at a reasonable price. I already have owned a 7400 some years ago. It is a great second rig for HF, especially during holidays. It carries 144Mhz at 100W output too. However listening to noise and weak signals on 144Mhz from this IF DSP rig was annoying to my ears. I instantly noticed a huge positive difference when I hooked up an Elecraft K2 +DEM 144/28MHz transverter. What a relief. Analogue beat digital. So out went the 7400.
In fact, in the past I have often parted from equipment which proved to be good in one area but were annoying in another. But the grass ain't always greener at the other side of the fence. Some years later I would buy such a rig again just because of its positive benefits. Maybe there is a learning point for me here?
Now the 7400 is perfect for 6m. Look at that huge monochrome backlit LCD screen; large frequency readout just above a high resolution S-meter. All info visual at glance without being the typical American x-mas tree. Icom designed a true icon when they released the IC746 back in '99 and the 7400 is even better!
Verdict: Instant gratification due to superb user interface & performance. Best in class ergonomics.

Icom IC756ProIII
A friend offered me to try this model for the weekend. I am familiar with its layout since I owned a ProII in the past (too?)for two years. Will this surpass the 7400 on a direct comparison? At Friday night I am already seduced by it's looks, it sure has the most beautiful analogue S-meter ever. If you can pick only 1 rig for your shack it would surely be this one (plus a 144 transverter). So I am a sucker for color screen LCD rigs after all?

During the weekend the 6m band has several Es openings, even some cross-Atlantic into the Caribbean area. I also tried this rig for one evening at another friends QTH who has a bigger 6m antenna. But how hard I try, there is no difference when it comes down to plain receiving performance when compared to my 7400.
The band scope with its slow refresh rate does not offer anything usable. Try using a real-time band scope like most SDR's offer and you instantly see what I mean. Since the S-meter is at a distance from the frequency readout I tried the optional digital S-meter. But it is a joke compared to the 7400. What a lovely looking rig, but it does not do what the 7400 does for me.
Verdict: No receiving advantage. User interface does not communicate to the operator like a 7400/746 does. Useless, distracting band scope.

50MHz transceivers I have "tried" elsewhere

This is surely far from objective. But at least in terms of ergonomics it makes sense to me.

Yaesu FT950 & FT2000
While visiting the Hamradio fair at Friedrichshafen I managed to take a look at these models. At the end of the day there was plenty of time to play with both of them. There is an outdoors antenna connected. The AGC is a disaster and it sounds horrible on spikes or nearby clicks. User interface is classic for the 2000 with a nice large S-meter. But this classic isn't ergonomical.

Icom IC7600
Looks like a downsized 7700. Larger but even slower band scope than the ProIII. S-meter is ugly and difficult to read; should have been given a shadow on the needle to make it look semi 3 dimensional at least.
German magazine FUNKamateur offered their monthly edition for free during the fair. It had a test on the 7600 where it was revealed this rig suffers from 10-15dB higher phase noise in the 2-10 KHz range, compared to the former ProIII. As the writer states; when using a VHF/UHF transverter, this rig is less interesting for weak signal reception due to its relatively high phase noise. One month later the RSGB review by Peter Hart notices the same issue, but is keen enough to call it measurement was noise limited.

Elecraft K3
Serial #173 is at my friends QTH for more than 1.5 years now. It is an exciting rig and has the best HF receiver, on paper. I have made several contacts on 6m with his set-up and large antenna. Filter settings below 150Hz are ringing, whatever the settings we tried. Ergonomically it is a disaster. Despite knowing the rig inside out, its owner isn't too happy either and finds himself using his Perseus SDR more often nowadays. I still would want one to add to my shack....someday.

Conclusions:
The Icom IC7400 offers me the maximum pleasure for 50MHz operation.

What's next?
There are some ideas left. First I need to recapitulate all results and efforts this year.

And then there's the newly announced IC9100. It has HF+6+VHF+UHF+optional 23cm.
The format is similar to the 7400; that's surely a good point.
However, with so many bands in one rig I hope they do not choose the cheap way.
And despite its good looks it sure must be better before I switch again.

Getting the most out of your rig; another mod for the TS570SG on 50MHz

2009-08-02T11:08:00.013+02:00

One is never satisfied ..
Quite regularly I'm trying to raise my 'Rig-Fun-Factor'. Finding a 'nicer rig' so to speak. That means that besides an inspiring user interface and great ergonomics, it must offer exceptional RX performance too. In short; it must look nice, be fun to use but also capable of digging deep in the layers of noise to catch that weak dx on 50MHz.
I have had the pleasure to use an IC746 for several weeks during a 50Mhz dx-pedition. But that rig had to be returned to its owner. Again I'm not giving up on the 570 yet.

My TS570SG does a great job but still can use some help RX-wise.
I have made some changes in the past (see my blog on 30 may 2008) being:

Added Inrad 400Hz CW filter
Exchanged std Kenwood SSB filter for Inrad 2100Hz
Added temperature controlled crystal heater (Kühne Electronics/ DB6NT
Tried external 50MHz pre-amp SP6 (SSB Electronics)

Still not being satisfied when comparing it to my 2nd 50Mhz set-up (Elecraft K2+XV50 transverter), I decided to take this one step further.

Modify the input circuitry of the TS-570SG
Looking at the schematics one recognizes lots of circuitry before the first mixer stage; low pass filtering, attenuator, bandpass filtering, 2 stage pre-amp, more filtering and zillions of pin diodes in the complex RX path(s). Using pin-diodes as RF switch is the cheap and easy way for any manufacturer.
There's been a lot of hype on the subject and I do not want to get into the discussion of how much noise and/or IMD distortion a pin-diode might create. I do not have enough experience in this area nor any equipment to measure the difference. But the fact remains that there are some 32 pin-diodes connected in or to the RF signal path at all times.
Why not get rid of all of the above and try something rudimentary?

Plan: Use external 50MHz pre-amp and inject its output directly into the 1st mixer, bypassing al front-end stages.

The SSB SP6 is a robust 2-stage pre-amp which already has a sharp helical bandpass filter at its output (See blog of 2 feb 2008). That covers the front-end +bandpass filtering. Next we need to determine where to inject the amplified 50MHz signal.

The block schematic shows the RX stages of the receiver input. Let's cut the RX path at the red marked spots.
If we forget about the attenuator and first 60Mhz low pas filter stage, we can take a short and simple route by using the 570's internal cable routing.

Just move the coaxial cable from CN1(RF Unit input) to CN7 (test point 1st mixer).
Now there's still some circuitry connected to that 1st mixer input. You need to disconnect that by removing just 2 pin-diodes.
See next picture for more details on how and what:

What steps to take:

Remove coax cable from CN1 and insert at CN7
Remove pin-diode D30
Remove pin-diode D43
Bypass R35 (5k6 at CN7 test point input)
Create proper RX/TX switching for the pre-amp, using the 570 REMOTE connector and a separate PTT foot-switch (the SP6 already has vox operation built-in, but it can't hurt)

Needless to say that the TS-570SG will not proper operate on any other band but 50MHz.
Don't try this at home if you have no experience in electronics. I can not help when Murphy decides to assist in your personal attempt.

Test and operate the new set-up
What do we have now?
A 50MHz pre-amp and a TS-570SG with an RX direct 1st mixer input.
Switch-on the rig and GO!
Interesting to see that it all works without quirks and/or additional smoke..... :)

On weak signal comparison the modified 570 seems now on par with the Elecraft K2+XV50 combo. It sure is more sensitive and also sounding different. But that is all subjective, It will take weeks of comparison before I can make a conclusion. But more important let's see how much fun I will have with this new dedicated 6m rig.

There's plenty of Es openings on 6m this season, see my 6m twitter blog. So let's enjoy this!

Es IV, more nostalgia

2009-07-11T12:55:00.004+02:00

President Madison
The Bentley of ancient CB radio.
I bought this rig via a local auction website. It is fully functional and has the following specs:

120channels, 40 low, normal, 40 high
AM/FM/LSB/USB
+10KHz switch for the so called Alpha Channels
Upgraded power supply

All is due to modifications done, as the unit originally only has 40ch and AM/SSB.
The mic is neccessary for operation of the speaker. Need to get that fixed sometime, cause I do not use this rig for TX.
The sound is lush and shows good selectivity. On opening the hood I found a real SSB IF filter having 6 crystals. Now that's truely amazing !

Now take a look at those large meters, they are dying for or what?

Es?
Ah yes, I'm drifting off again. Sorry about that.
The Madison is for 3 days in use now and usually parked on 27.555 (triple-five). Its sensitive receiver shows Es openings already from 09:00 (local) onwards from Italy (what else is new) and later Spain. At 10:30 the band is filled with many loud signals from all southern Europe.
And 6m, which was quiet for two days in a row, is starting too. I'm hearing Italy, Greece and some Ukrain stations.
The Es openings on 27MHz come in waves too, just like 50MHz. However, there's always life on CB, whereas 6 usually stays total quiet in between.

I need to start becoming active on 28MHz again.

Es III; Building antenna's just for the fun of it

2009-05-27T16:09:00.026+02:00

Seasonal holidays on Thursday and Friday.
Two days free from office stress.
Dry sunny weather.
Fresh Diemme coffee beans, grinder and Gaggia Espresso machine.
YL on a 5-day trip.
These are the perfect conditions for a few days out in the wild. Errr... the antenna backyard that is.

Step 1: collect aluminium

Collected all aluminum of the 7el 50Mhz long yagi which we succesfully used in HB0_2008. Taped it to my bicycle and of I go. What a nice way to start the day :-)

However, it turned out I missed the long middle boom-section. So after a nice espresso & cappuccino we collected the other antenna parts, including another 5el version, also home made. Us have plenty of (home made) antennas by now. It has paid off well. Both in the fun of building them, as well as using them.

My hybrid sports-bicycle has a pretty short wheelbase. And that is VERY scary with this pile of alu tied to it. As soon as you make a turn the alu is trying to keep going straight ahead and starts shaking its head and tail. The whole bike starts oscillating and that makes each road turn a struggle.
The second standard dutch city-bicycle (ages old model) did not suffer from this effect.

Step 2: build antenna

Empty transport boxes from last summers HB0 dx-pedition. Find baseplate, connection box, coax transformer and several brackets. Locate that carton of very special screws. Drink some more espresso & cappuccino.
Start building the element brackets again.

TiP: through the process we learn that it (would have been) is very important to proper indicate all parts involved, for future reference (yes, please?).

That ends day one. Time for some espresso & cappuccino.

Step 3: mount mast construction
Local rules and neighbourhood control prevent us from building a giant mast. But an antenna is an antenna and certainly beats no antenna. Next, Rens' garden has an almost free view to the west with very low noise. Opposite to my home situation, which makes this a valid remote rx site. Now let's start with some fresh espresso & cappuccino.

Stones are 10cm thick. A special mounting screw for professional use in machinery is being used.
Top bearing and G-1000 Yaesu rotor are added. Time for some lunch and more espresso & cappuccino. Not that you think we started already at "ooh-eight-hundrud". No way, it's holiday time ;)

Step 4: hoist up the antenna

At this relatively low height the antenna is easy hoisted up and mounted to the mast.
Both seriously sweating here under the direct sunlight. Now the 20m Ecoflex-15 (15mm dia) coaxial cable is attached and connected to an Elecraft K3 +pre-amp.
Let's catch some multi-hop-Es dx.
Fire up all equipment...... and .....
Band closed.
Time for some more espresso & cappuccino.

The 50MHz 7element, PA3FGA design @10mtr AGL, QTF caribic.

Step 5: fresh pork
Earlier this day we visited an 'old fashioned' butcher. One which cuts the meat in their back shop. Not any vague import meat from far-far away. No supermarket pre-sugared-thin-slices-crap.

Make fire.
Start with some lovely marinated spare ribs.
Next the real stuff.
Only meat today.
Certainly NO vegetables or salad-trash to upset your stomach.

Now, there's always room for a finishing espresso & cappuccino.

You get what you.......

2009-05-24T11:25:00.003+02:00

Ok, what's wrong in this picture?

Issue #1
N-socket nicked, coming loose from its mounting plate.
Also some nickel plating chipped off on the right.
Result from rough handling? Wrong tools / overtightening the applied N-connector?

None of this all.
Its the Heavy Duty N-connector and Ecoflex-15 (15mm coax) which did this in just 2.5 weeks during our last fieldday setup in HB0 at 2020mtrs ASL. Despite the coax being taped to the boom, it put too much stress on the socket while being turned. Needs better fixation against self rotating,more slack around the rotating mast etc... next time.

However....
Looking at this type of socket we need to invest in better quality stuff whenever it matters (doesn't that always?).
It became a habit of locating a good deal (read cheap) of connectors & sockets at every hamfest we visited. Nowadays we are more serious on buying large qty's of the good stuff together with other hams from:
www.RFParts.com
UKW Berichte
Kabel-Kusch

So the nickel-crimped version is exchanged for a machined silver teflon version.

Issue #2
Spotted the rust color on the top edge of the socket on the 1st picture?
That's not from the socket, since these are made from chrome plated brass. It's the 4 mounting screws.
From the local DIY store, type galvanized. Equivalent to: lasts one weekend.

Now you might think "buying Stainless Steel ends this, right?".
Not really.
There are plenty of "SS" versions around and the ones with real durability are difficult to find. Your DIY store probabely only has the (again) cheap version available.....

So..?
I know; not every single screw needs to be 100 micron goldplated, navy-proof and such.
But think again when you come across the next auction of cheap stuff.

Es II

2009-05-01T20:55:00.006+02:00

Trick 1a: monitor Es propagation on 27Mhz SSB
For 2009 I promised myself to pull some extra rabbits out of the hat.
Remember the old CB SSB contacts during the evenings in the 80's? We thought that making contact with South-France, Spain, Italy etc.. was the ultimate dx. What did we know about Es propagation back then when I was only 16? With 12W in SSB, 120 channels etc. (non-legal) and a simple half wave vertical on the roof, next to girls&cars life was exciting to the max!

So why not monitor some CB SSB frequencies to detect Es openings?

A quick jump in a pile of old gear and I dig out both a legal CB rig (22 channels, 0.5W and FM only) and a typical flea-market-worn-out-120channels SSB true DX-rig.
Within milliseconds after switching it on I receive colourful memories from the past; it's that analogue S-meter. This type S-meter was used in most CB rigs in those days and although it looks miserable small, it resembles my youth. I have stared for zillion hours at that tiny needle. Those were the happy days. Yes sure they are.

La Lafayette seems way off frequency, the SSB section is horribly mis-aligned, no TX, but who cares?
Ok, now where do we connect it to?

Trick 1b: a quick home made vertical for 27Mhz
That shouldn't be too difficult. Grab a short fishing rod and cut some wire.
The quarter wave vertical, using 1 radial, is quickly mounted to the side of the chapel roof. Some fiddling with the antenna analyser and we're done, right?
At first I get a resonance at 25.2MHz and it seems parked there, no matter what lengths I cut. It turns out to be the the aluminium strip at the roof front edge, which is very nearby and exactly in resonance at...... Anyway, moving the radial just 1m away from it and the resonance goes up more than 3 MHz. Now both lengths are too short! I feel like an idiot.
Anyway, half an hour later we have CB antenna capability in the building.

The Lafayette offers muffled LSB signals from Mediterranean countries, thus proving there is Es going on.
Can you remember the 'old calling frequencies'?

26.620 South Africa
27.450 France
27.555 General calling freq. but mainly Italy
27.765 Germany, Austria, Switzerland
27.805 Holland + Surinam

I think I better keep it parked at 'triple five'.
Let's see what this trick will offer me, besides some nostalgic feelings :)

Worked some more countries on 6m during Es: 9H1 and an IT9.

Es

2009-05-01T15:42:00.006+02:00

2009 Sporadic-E Season on 6m has started !
I witnessed some minor Es openings on two evenings in a row, but that was between Spain, Italy and SV.
Never expected it would happen up here in Holland that soon.
However, this afternoon we enjoyed a short but strong opening direction South Spain, Marocco and the Canary Islands.
I managed to work EA9IB. That is country #4 this year.

See ON4KST screenshot below with lots of humor in the text.

Location, location, location..........

2009-04-12T16:26:00.022+02:00

Another measurement?
I like spending my hobby time spinning that VFO, searching for that new signal, working a new country, give away points in a contest etc.. I'm not the type who sits hours at his workbench doing some serious measurement, endless building/soldering etc..... unless, it can bring me new qso's.
Nothing beats being able to hear more, unleash another layer of signals from the mud. For that reason I like trying new hardware; other antennas, other RF equipment.

Being able to make that extra QSO yes/no. That is my most important criteria when doing experiments.

While there is plenty of well documented information on the web, every now and then you really do need to verify matters before making a decision on what step to take next.

The Perseus as a measurement tool
I have shown earlier that the new Perseus SDR receiver has some pretty good options in its receiver user interface. I did some quick 6m band frequency sweeps in 3 major directions, see my previous blog. Having the Perseus on loan for some more time, the next logical step would be to do noise mapping at my current home for 50 and 144Mhz.

Current antennas for 2m: 17el and for 6m: 5el

What exactly is being measured?
A band segment of 6.3Khz is carefully monitored for its band noise level. I have chosen 144.461 as the centre. This is right in a clear spot of the beacon section. The found level of background noise is noted and put in a table.
This is time consuming since you need the level to settle in on the averaging and you want to monitor the band behavior for some 20 seconds at least. After some practising for a day or two, I was able to make reliable measurements within 0.5 dB.
The antenna is turned in steps of 10 degrees. In total 38 directions are monitored; the two steps overlap are for verifying earlier found values.

IMPORTANT: the diagrams show the difference from the quietest measurement. It does NOT show absolute noise levels, only the delta.

144Mhz noise mapping at my QTH
The receiver set-up consists of the following:
17el Tonna yagi @13mtr AGL, aperture angle@-3dB:33 degrees
25mtr Ecoflex-15
Elecraft XV144 transverter, including the crystal oven option
Perseus SDR receiver
Settings: span 6.3Khz centered at 144.461MHz, averaging at 80%

Time slots: 00:30 UTC, 07:00 UTC, 11:00 UTC, 18:30 UTC

Comments on the 144MHz radar view at PA5MW:
The worst directions offer between 6.5 and 9.5 dB more noise disturbances. Go figure! Even in the middle of the night(00:30 is at 02:30 local) there is a horrible RF noise from 3 major directions.
My house is at the east border of the town. I'm lucky that my QTH is at a slightly higher level(+2-3mtrs); at the highest spot in town. I recognize the quiet area from 30 -160 degrees. QTF 290 is pointing at 6 apartment buildings, 10 storeys high, which are at a distance of about 1100mtr. QTF 190 I cannot really explain yet.

In order to verify the whole testing procedure, I did a similar quick test at the QTH of PA3FGA. Rens lives in a much smaller town(2240 inhabitants, compared to the 30000 in my town). His set-up has the exact same 17el Tonna yagi antenna and the same Elecraft transverter. He is able to extend his tower to a max height of 24mtrs. Because of wind and time restrictions we decided to do two measurements; one with the antenna at 12mtrs AGL and one at 16mtrs.

Comments on the 144MHz radar view at PA3FGA:
Although Rens is suffering from much less band noise, he is plagued by disturbances from my city in the direction of 160 degrees. Which is actually the exact QTF for his favourite 2m beacon, HB9HB from Switzerland. The other two lobes point at two other towns. Lowering the antenna involves less band noise, but also less tropo signal from the dx beacon in HB9. We spent another evening finding the optimal height for maxiumum signal/noise level. However, the constant QSB spoiled any possible measurement. From experience we know that 18mtrs is the optimum height for best s/n on tropo signals at his QTH. Due to the wind we were not able to confirm this using the Perseus setup at this point.

50MHz noise mapping at my QTH
The receiver setup consists of the following:
5el M2 yagi @11mtr AGL, aperture angle@-3dB:42 degrees
20mtr Ecoflex-10
Elecraft XV50 transverter, including the crystal oven option
Perseus SDR receiver
Settings: span 6.3Khz centered at 50.087MHz, averaging at 80%

Time slots: 01:00 UTC, 06:30 UTC, 12:00 UTC, 18:30 UTC

Comments on the 50MHz radar view at PA5MW:
The giant noise lobe which peaks between +8 and +10dB from QTF 280 to 360 is an eye-opener for me. I have spent too much time on worrying about my less than average ability to hear the USA on 6m. I can work them usually easy at first or second call. No wonder! I simply have 'bad ears' towards that direction because the band noise level is much higher than other directions.
The other big lobe, which is evident on the 144Mhz view, also exists here.
During the night all is relatively more 'quiet' than on 2m.
One can also pick the wrong time slot; I started measuring at 17:45 UTC when just before 18UTC the noise suddenly became outrageously high. What had just happened? Well, since the start of television people turn on their TV's for the 8 o'clock news. During the first minutes a tv produces its peak of EMC noise. I waited some 30 minutes and did the measurement again. The evening disturbance sure is a bummer on 6m.

Conclusions:

Noise levels at my QTH from various directions differ MUCH more than expected; up to 10 dB on both 144 and 50MHz.
My direction for dx would be roughly east between QTF 30-160
I cannot concur that with pre-amps, better rig or just another antenna
Going extremely high and using a stack with a low noise temperature is not feasible for me
Live with it and change operational tactics to make the best out of it

Does this mean I cannot work dx, not have any fun anymore? No, of course not. First of all, my current QTH is a lot better than my previous location. That was in the middle of a large city, and although my antennas were at 19mtrs AGL(6m higher than currently) I suffered from even more noise in every direction.

One very important matter: no hardware is going to solve that wall of 10dB noise.

Next question is: what is the relevance of those found minimum levels? When is your QTH a quiet loation?
In order to do a comparison test we need to design a portable setup and do several measurements at many different locations, both urban and very remote.
For now I need to accept the situation and make the best from it.
It is what it is.

Linking K2 to TS570SG in a master-slave configuration

2009-04-09T17:50:00.010+02:00

New goals for 2009 6m season
The 6m season will start in a few weeks. There are a few enhancements on my wish list.
One of them is to link my Elecraft K2+XV50 transverter to the Kenwood TS570SG.

Why would I want that?

Make use of the best ergonomics
On 6m it is usually a matter of seconds to find the dx and make the contact. Better rig ergonomics do help a lot. The Elecraft K2 has a great analogue receiver but ergonomically for me it is very annoying. The TS570SG has superb ergonomics, and a quick& friendly user interface.

Better TX signal from the TS570SG
It has a much better mic compressor, high-boost equalizer and 100W output on 6m.
The K2 +XV50 has none of that.

Make use of a second RX
- For monitoring a different frequency.
- Because I want to try some semi-diversity (pseudo-stereo) in the audio chain. That requires some more work; like a second switch able antenna and switch able audio routing.
- Finally because the RX quality of the K2+XV50 transverter might offer better performance. Well this one has to be proven yet, since I have already modified the TS570SG again to make it a dedicated 6m rig only.

Remote operating
It will serve any remote operating experiments too.

Conclusion
I want to operate the TS570SG, but be able to co-use the K2 on the fly.

A programm to master-slave the K2 to the TS570SG
Since the K2 uses the Kenwood protocol, it is possible to create a program which enables to make the K2 follow the TS570. I'm fortunate that Arnold wrote a small program which just does that. It reads the current VFO-A frequency and writes this to the K2's VFO.
After just two evening sessions we have a raw but working program. I can now turn the Kenwood's VFO and the K2 follows quick enough to avoid any latency and such. We still need to work out some minor bugs and make it more operator friendly, but for now it already does what I wanted. Great job done Arnold !

There a some minor frequency difference on the readouts of both rigs, but that is due to the offset of the K2's 6m transverter. It is key to zero-beat both receivers. I have to do a lot of testing to see if both behave well and do not suffer too much from thermal drift and such. A quick user offset setting will probabely be the next added option in the software program.

Buy another rig?
Now you might ask why don't I buy a new, better rig with dual receivers (or dual watch) and everything else I need? Well there's the financial aspect, and more important, I'm not ready to give up on the 570 yet :)

Location, location, location..........

2009-04-05T08:05:00.011+02:00

PERSEUS
I'm lucky to try out the new PERSEUS SDR receiver from Microtelecom.
I have seen it in action at Rens, PA3FGA for several weeks now. It IS a great device.
What I like most of it:

It does have a great receiver
Very informative GUI, much better than any SDR competition
Can show both waterfall bandsweep and separate FFT spectrum on the received passband
Can record 800KHz band segments at a time (record the 48hrs contest)
Has reasonable measurement capabilities for frequency analysis

The waterfall view together with a small bandsweep and proper averaging settings is the way to find weak ones. I have seen proof on very weak beacons on 144MHz (from my Elecraft XV144 transverter output). I have also watched a recorded night of ARRL-DX-CW contest on 160m. You can spot the weak ones next to the big pistols. Yeah key-clicks are now visual too on some of you :)

Measuring device?
This is a consumer device, but with valuable user settings and good specifications.
As such, it can be a reasonable measurement device with which you can do some rudiment frequency analysis. It is capable of showing clear raw data you can trust.

Now what has it shown me so far?
My current location at the east outer border of a small town has shown me already that I suffer from noise and in band disturbances on both 50 and 144 MHz. When turning the antenna, both the ground noise level rises and several in-band local disturbances turn up.
For 50MHz this is very obvious when turning the antenna to the N-W direction (my town).
Time to do some of that frequency analysis.

I did a bandsweep from 50.000 - 50.200 MHz using the following setup:
5el M2 yagi @12mtr AGL
Elecraft XV50; 50Mhz to 28MHz transverter
Perseus SDR receiver set at 200KHz span and averaging set to 80%

6m band direction N-E (QTF 60deg)

The window is centred on 28.100, which effectively is 50.100 MHz. The transverter is aligned and has the crystal oven build in. Do not look at shown levels and such as this depends on many factors.
The disturbances on 060, 090, 120 and 150 are local man made QRM.

6m band direction South (QTF 180 deg)

See the effect of local noise? The band noise level has already gone up by 5 dB and new other disturbances turn up.

6m band direction N-W (QTF 290 deg)

Even more noise and stronger disturbances.
The measurements where made at 03:00 in the middle of the night (01:00 UTC), when all is quiet. Right?
Think for a minute what it might look like during daytime, or even worse, during evenings?????

Preliminary conclusions:
This is a quick&dirty band scope view only. It only shows the 'Big Picture'.
It might explain, to some extent, why making contact to the USA on 6m is so hard from my current location. However, there is much more measuring to do before jumping to conclusions.

Next?
Perform extensive testing in more directions, at different times during the day.
Repeat the measurements to average out any large variations.

Receiving splitter II

2009-03-26T20:48:00.010+01:00

Another one?
Yes; in my previous blog of January I mentioned needing another splitter.
It would need a better spec at 28Mhz. The IF output frequency of my 144Mhz & 50Mhz transverters.
I have plans for:
- analysing signals during reception
- comparing different IF rigs at readability
- combining different IF rigs to create sort-of-diversity reception

And not for?
This blog is not for writing a paper on already existing applications, home built equipment and such. There are lots of other, better web resources for that, like: W8JI, VK1OD, hard-core-dx to name a few.
I just want to record my findings and describe the equipment used while in the process. It will serve me when picking up a project again in the future.

What do we have so far?
A quick & dirty W8JI style Magic-T combiner, using #73 ferrite binocular.
The frequency sweep shows the port to port isolation from 1 to 30Mhz.

W8JI version Magic-T splitter_MKII
A more serious attempt this time, using:
- alum die cast box
- #43 ferrite binoculars
- 24 AWG red enamelled wire
- BNC chassis parts, pop riveted to the box
- 1W 100 Ohm metal film resistor

I have ordered carbon composite resistors. If that offers a significant better specification at 28MHz I will do some more testing and create additional versions of the splitter. When time allows.

How do they compare?

attenuation port to port isolation
1.8Mhz 28Mhz 1.8Mhz 28Mhz

MKI -3.52 -4.33 28.0 15.5
MKII -3.05 -3.30 38.0 19.2

Remarkable that using #43 ferrite brings better specs at 1.8Mhz, right?
There sure are other possible reasons for that: using a shielded box and different wire.

Other remarks:
Port 1 to Port 2 isolation and vice versa differ 1 to 1.5 dB.
The measuring coax cables have been calibrated in the test set-up by the HP network analyser.
The cables (RG58) might have a small negative influence on the isolation measurements due to the limitation of their shielding.

Satisfied?
Yes; it has low attenuation, sufficient port-to-port isolation and it is easy to reproduce.
Let's get using it and do some of the tests I've on my mind.
I'll be back.....

Backyard 7 Mhz Vertical

2009-03-22T10:52:00.008+01:00

For the sake of making contacts on the 'upper' Low Band I decided to do a quick & dirty GP set-up for 7Mhz.
The current 'Simple HF Multi band Vertical'(see previous blogs) had to go. There's no sunspots to expect in the next coming months, so no interest in the NCDXF beacon monitoring station currently. Even more because I have Hi-jacked the TRX (TS570SG) for the coming 6m season.

How to create a simple backyard GP

1. Make a full size radiator
Take a typical fibre glass fishing rod and any kind of conductive wire. Note: insulated wire intruduces a velocity factor of about 0.92 - 0.97, depending on the insulation type and thickness. Now start calculating the 0.25 wavelength, using the lowest frequency you want to be able to use; add another 5 % for adjustment.
Slightly spiral wind the wire around the rod and use electrical vinyl tape to fix it.

2. Install a ground rod
Just hammer(-drill) down any kind of 1-3m length copper pipe. It serves as a lightning rod and makes a good bonding point for the radials. Note:it is does not protect against a direct hit. When zapped by lightning it might avoid that all your shack-gear is toasted. There's lots of good websites on that subject so take proper care and be responsible.

3. Lay out some radials
Again; use whatever conducting wire you have available.
My backyard is 7 x 8 mtrs and the GP is mounted right at the corner. So no space available for 120 even spaced 'full size' (what is that crap?) radials. Just lay down whatever you can manage. I have 9 lengths between 4 and 8mtrs spread around the backyard. It covers 110 degrees around the GP. Why not 360 degrees? Simply because there is no space available.

4. Add a current balun.
Take a proper piece of ferrite (FT150A-K), put 8 windings no 16 AWG Thermaleze wire on it. Some 10-12 windings of thin teflon coax on a proper ferrite will be a good alternative too.
Use proper protection against moist.

4. Adjustment
Do the adjustment after you have layed out all radials. Adding more radials can alter the radiation resistance and shift the resonance frequency, certainly when you have only a few lying around like in my example. But my point was not to create a High-End antenna (what is that?), only to start being able to make contacts on another band.

How does it perform?
We have a full size vertical (3 out of 3 points), a ground rod + 9 short radials, covering only 110 degrees between north and south-west(1 out of 3 points) and a tiny backyard in a small village (2 out of 4 points). That makes 6 out of 10 points on the 5MW scale.
Within 24 hours I make numerous contacts to the USA and several to Asia. There are no radials in the direction of Asia, but I get through the pileups of BY and BV without severe drama involved. My operation is CW (only) and at a max. of 50W
Let's face it; ANY kind of antenna will allow you to make contacts. And depending how many effort you put into the process, you can master fine dx contacts at will.

Am I happy?
The antenna is up since February 6th and does perform as one might expect.
However, I kind to start disliking the band. Or today's hamradio operators behaviour to be more exact.
The art of rudeness and jamming from so many, makes me shutting of my TRX to often. If I would be able to put more effort into a directive high performing receiving antenna I might avoid them a bit. I also wish the dx-clusters would cease to exist. Tomorrow please..... ??

Anyway, time to return to my roots on the Low Bands: 160m !

Beverage antenna II

2009-02-22T21:41:00.002+01:00

Did someone mention 'Beverage Antenna' ???

Beverage antenna

2009-02-16T18:37:00.008+01:00

Preparations for the beverage antenna(s)
Last weekend we secured a potential new contest site. So now it's time to test & verify new RX antennas.
First stage: compare high performance beverage antennas.
From the junk-closet I digged out some 4 similar built beverage boxes. We need 5 pcs for the stage 1 test, so I used this evening to copy cat a final 5th one. I have used this type of box from 1990 onwards, and this is the latest portable version. These are very comfortable for field day style use.

Above picture shows two finalized beverage connection boxes. These consist of the following parts:
- TEKO plastic box with alum top cover
- Connection terminal with both wire and banana plug entries
- BNC female chassis part
- 4x M3 bolts & nuts
- Silver coated 3mm solder lug
- Teflon coated wire
- Binocular ferrite type 73
- Hot glue
- Wet Basis Protect performance spray
- Liquid tape

The balun consists of 6 primary windings and 2 secondary windings using thin teflon coated hookup wire.
Hot glue is used to fixate the balun. This avoids broken wires when the box drops on a concrete floor.
The Wet Basis Protect performance spray protects electrical components against moisture- and humidity-related short circuits, malfunction and corrosion. It prevents subsurface penetration of moisture and performs a permanent protective film. I have used this for 2 years now and it has shown great performance on outdoors applications. It is sprayed on all metal parts in- and outside of the box.
The liquid tape is used to protect the M3 bolts and the box from moisture via the BNC chassis connector.

Test & verify and re-test again

There is no room for building errors in our next RX antenna experiment. I need to be absolutely sure the beverage connection boxes work as predicted.
The antenna analyzer shows a flat response from 1.5Mhz (start freq. of the analyzer) till 10Mhz (and even above that but who cares?) with a 470 Ohm resistor connected to the beverage box. All 5 boxes with top cover mounted are DC measured as well as tested on the antenna analyzer.

Five finished & tested beverage connection boxes. You will appreciate the builder's consistency in the construction.
On the right an already newer version is shown. This one has a full weather proof box, better suited for permanent installations.

What's next?
- Copper ground pipes + termination resistor + beverage wire connection terminal
- Ground connection cables to the box
- Time to put that pizza in the oven

Having stuff available

2009-02-15T19:03:00.024+01:00

In our hobby it is very convenient if you continuously have all possible required parts available for 'the next project'. This story concerns bragging about pulling the rabbit out of our sleeve on demand. But to be more seriously; this is where we have grown over the years by carefully choosing the right parts, and buy large quantities each time, at flea markets and keeping so called 'obsolete old stuff' conservatively stored instead of throwing it away. Also, if you can build something and it works well, build more of them as they will become handy in time.
But it is not at my place, it is at my friends QTH. His garden is growing all kind of vertical constructions all the time, year in year out.

K9AY and Magnetic Loop
To put PA3FGA's K3 and the all new Perseus to the test, various RX antennas are put up and compared against the short 160m reference vertical in the front garden. There's also a wideband NVIS dipole at 1m70 height available. Mind you, we do test antennas 90% for 160m use.

The K9AY antenna box is my MKIII version. It was build just before a test-weekend on Friday night in total darkness. We started with a brand new version MKIV, which earlier during CQWW CW in 2008 at our PI4TUE club station, showed open circuit 100nF caps. While trying to do the F/B adjustment on the termination resistance, other problems turned up. That's where the available old MKIII antenna box was put in action again. It's nice if you have spares available :)
The second antenna is a simple magnetic loop made from a 5mtr length 22mm dia copper tube. On the top a water bottle (rain protection) contains a strap of doorknob capacitors. On the bottom an FT240-K ferrite with 8 windings inside another bottle holds the 50 Ohm output coupling, followed by a coaxial common mode filter.

The magnetic loop is mounted to a thickwall glass-fiber pole, which in turn rests on a spare antenna rotor. At first it was mounted at 1m from the ground only. This gave it a low Q and thus a relatively wide BW. At this new height the BW has narrowed to a more relevant 20 Khz.

How do they perform?
The K9AY, after careful alignment of the termination resistor, shows 2 to 5 S-units F/B on 160m. Times the 3-4 dB (which is average for S-meters) we get a result which is common for this antenna. This version of the K9AY is our 10th time we have set it up and the 3rd time in this backyard. It is a useful RX antenna in which you can quickly switch in the 'backside null' in 4 directions.
The magnetic loop has narrow nulls off the sides and after some 5 weeks of use it does not show any real advantage over the other available RX antennas (short vertical, K9AY and NVIS).

Let's do 7 MHz antennas this weekend
Not only because we want to listen on 40m but Rens, PA3FGA also likes SWL AM broadcasting on 41m shortwave. He wants a full size dipole, hung from the available glass-fiber pole and a resonant vertical for comparison( actually that last one was my idea). So the K9AY and the magnetic loop have to go.
The K9AY central pole is lowered, the guying wires winded on the cable reels. The anchors pulled out of the lawn and cleaned. The MKIII antenna box removed and all stored in a box for the next possible field operation.
Two lengths of wire are cut for dipole resonance. Now for connecting the central coax a current balun is needed. Let's see what we have in the box?

The ferrite and copper wire were bought from Amidon (or their supplier CWS ByteMark for that matter) some years ago. On the right you see ready-to-use build versions in a box; the white one is an FT240 type 67 toroid and the green one is a type K. The #67 is better suited for 20-10mtrs, the K version is better for the low bands. We used these in our multiband verticals during summer holidays in Liechtenstein/HB0.
The other pre-wound baluns have F150A-K toroids and multi inputs suitable for 12.5/18/25/28/32 Ohms depending on which winding taps were chosen. See the book of W2FMI for details on this. All baluns are XXXL style built and way overrated.

The above balun was our first one build. We used this on a low full size 160m dipole and tested this during the CQWW-CW contest in 2003 on a farmers land and a portable set-up. We made 200 qso's from 21:00 till 00:00 during Saturday night, just for fun! The balun is not black-burned; it is a coating spray against moist. And the little box normally holds...euh held some of the lesser used spices in the kitchen closet.
The 3Y0X hat is only for cold weather protection.
Rens sent in the log and got rewarded by this diploma. I recall that I was the op at that time... oh well today's story was about bragging, right?

The full-size 40m dipole is quickly hoisted up to about 10mtrs AGL and attached as an Inverted Vee to anchor points left and right. Coax was already available from the magnetic loop experiment. A quick check on the network analyzer shows a wide dip at 6.9Mhz. Good enough. The 40mtr band ends at 7040KHz for TX anyway :)
Next we collected the 7mhz vertical+ top loading capacity hat (see my earlier blog from sept 14th 2008) from his garage and put it on the mounting post in the middle of his backyard. This is a fixed mounting location with a 3mtr 22mm dia copper ground pole, some 8 buried radials and a buried Ecoflex-10 coax going to his shack. It has served many, many (test-)antennas already. A 5-minute job only and we are also in business vertically polarised with a perfect SWR.

The right leg of the INV-V is attached to a convenient tower section, which was extended by wooden stick( a spare garden tool). You see, it's always wise to keep also tower parts available!
We had to cut some branches high up in the tree. These would otherwise tangle up with the other leg.

How do they perform?
On saturday evening the PACC contest is on and we monitor our clubstation PI4TUE efforts on 40m. On large distance contacts their high dipole (@70mtrs AGL) hears Asia and USA better, but on the short to medium distances our lowish Inv-V is clearly the winner. Just as what might be expected. The vertical offers more man-made noise and still has to show its dx capabilities in terms of signal/noise yet. But it is an early first night. We will have to test these antennas for some weeks.

What antenna do we want to build next?
As we are restricted by domestic garden boundaries, the list stops at:
- NVIS dipole wideband (2x8mtr legs@1m70 +32:1 balun) up in the side yard
- Inv-V for 40m up in the back yard
- Short vertical with capacity hat for 40m up in the back yard
- Short resonant RX vertical 160m up in his front yard
- Full size Multiband 10-12-15-17-20m 0.25 grounded vertical up in the side yard
- Short resonant phased RX verticals 160m
- K9AY (several)
- Full size multiband 30/40m 0.25 vertical
- Extended 40m vertical (11m85) with short elevated radials (1/8@4mtr height)
- Full size Multiband 10-12-15-17-20m extended vertical with resonant elevated radials
- Magnetic loop (2 different heights tested)
- Inv-L 160m with 12m vertical part + 2 elevated radials (fire in da hole!)
- Short 160m (23m)vertical with center coil
- Various multiband antennas preparation for field use (HB0-2007&2008)
- Commercial trapped 10-40m vertical (abandoned, bad performance)

The above corner shows some 'spare tools for ground mounted verticals'. The other pic shows some plastic posts, convenient for your vegetable-garden. And for beverages. There are some 150 more in his barn.
Rens is not married. His YL allowed all this in their garden and even recently build a K1, and a K2.
Life is a matter of priorities

I'm going to bed now :)

Receving splitter

2009-01-28T23:05:00.006+01:00

W8JI 'Magic T Combiner/Splitter

For feeding the RX inputs of both my Elecraft K2 and TenTec Orion with the same RX antenna, I'm in need for an antenna splitter.
Tom has great information on this subject on his website at http://www.w8ji.com/combiner_and_splitters.htm

I have choosen the design with the 2:1 step-down transformer and the T-combiner using the proposed type 73 binocular ferrites and some thin teflon coated silverwire I have in my junkbox.

Don't forget the 100 Ohm resistor as I did initially, or you end up with a miserable port-to-port isolation!
Measurements show a port 1 to port 2 isolation (and vice versa) of 26dB at 1820KHz.
I'll be using this splitter for the lowbands, mainly 160m so this will be sufficient.

Antenna connectors in your system; TRX vs RX only
Since my home setup is becoming larger, now that I have more antennas put up, I figured it would be a good idea to make a decision on using a different standard connector for all RX antenna wiring in my shack. You don't want to end up accidently transmitting into an RX antenna, or RX input of any rig.
There are currently 3 popular RX connector types:

F-connector; commonly used in the USA in combination with the cheap available RG6 coax
Cinch-connector; used as RX antenna input on most transceivers
BNC- connector; professional and reliable, used on transverters and Elecraft transceivers

Discussing with Rens/PA3FGA, with whom I do a lot of ham experiments, we decided to use BNC from now on only. I had some available as you can see, but there's certainly two items on the list for the next HAM flea-market :)

RX patch-box with common mode filter
Now is a good time to remove the bunch of heavy coax and stuff from the back of my Orion and create a separate 'patch panel' setup with a coax common mode filter. The coax is 2.5mm RG316 Teflon type. The ferrite core is an FT150A-J (#75).

If you look carefully you will see I missed something in the whole process. Anyone noticed this ?

The new RX patch panel board
No big deal yet, but it's a start.

Does it work?
Sure it works fb!
The Orion is true king in reception on 160m. However, the K2 is in its own league, especially when using the analogue audio peaking filter.
In just 30 minutes I heard 5x JA and 1x USA on my short 20ft reference vertical. At 22:30 UTC that is. Conditions on 160m are simply marvellous these these days

Future wishes?
Yes, I want another one for field day use. And another for splitting the RX output of my 144Mhz transverter. That is on 28Mhz where the above splitter shows only 15dB port isolation. So I will need to carefully design a different splitter using a more suitable ferrite, like #43 or so.

New 430 MHz antennas part II

2008-12-31T16:19:00.007+01:00

Finally a relay was found
The previous mentioned coax relay type CX520D was found, but it is way too large to fit inside the weatherproof box and have 3 N-connectors connected.
Some more digging inside the junk closet offered a smaller version CX120A. This one has direct solder contacts with 5mm coax entries. After several unsuccesfull direct plumbing attempts, I decided using 5mm teflon RG142 coax as pig tails. Perhaps costing some tenths of dB due to possible minor SWR mismatches, but then again loosing the N-connectors is already 2x 0.15dB (theoratically).
Ah forget about the dB-Bullshit; it will offer fine QSO's I'm sure!

Not the slickest looking solution, but done with care for reliability.
The IP66 plastic box outlets are weatherproof, but I added liquid rubber for additional protection.

The coldest night in Holland for 2008
Early this morning I found that the 430Mhz omni vertical was affected by last nights -9 degrees celsius frost. Our coldest night of 2008 !

That is not white paint but frost; see the close-up.

The coaxes are cut and have N-connectors.
Another antenna preparation ready for the soon-to-be antenna overhaul.

New 430MHz antennas

2008-12-27T14:48:00.004+01:00

There's currently a lot of VHF/UHF antennnas lying around here. Some from fieldday setups, holiday/contest packet links, or just waiting for 'that new project'.
Well since there is very little activity in CW/SSB on 430MHz, I never got to setup a decent yagi at this new QTH. I'm not into UHF dx'ing anyway; my focus lies on 50/144. You can't do all bands, unless you spend (too) many time in the shack, right?
FM repeater dx'ing is something I do like and since I'm preparing new omni-verticals, I decided to add one of the available yagis to the new mounting bracket.

This is a Flexa type FX7044, 16el for 430-440Mhz. Boomlength is 3.10mtr. The Flexa Yagi, is extremely light weight (1.7Kg) and has the lowest windload on the market. Its 2mm dia steel elements are subject to discussion in terms of achievable gain, but for my application it is perfect.

The white spots indicate spray paint. It is a special spray paint which can be used on all surfaces and even rost. I'm using this for endured weather protectection, other plastic sparys etc. never did last very long.

What's next?
Both antennas connect to the same UHF rig, so a coax switch box is needed.
There must be a CX520D coaxial switch somewhere in that closet.....

CQWW CW 2008

2008-12-04T23:42:00.017+01:00

Preparations at PI4TUE
To tell you the truth: not many of us were prepared for this contest. Domestic issues, heavy workload @QRL and stuff, prevented us from a decent preparation. However, Aurelio/PC5A did a great job in getting the clubstation PI4TUE ready on time. He had to climb the roof tower on friday afternoon before the contest, to fix the SteppIR, which again had a major tilt and azimuth offset. It just will not clamp.

We set up our only RX antenna, a home made portable K9AY, just 4 hours before the start of the contest in darkness. Initially it showed no directivity whatsoever. We could not find any error but noted that disconnecting the ground had no effect. The ground connection consists of a 1m copper pipe and 4 additional radials. Usually the ground stake is sufficient enough. Adding the radials makes this antenna even work fb at a rocky 2030mtr ASL mountain top. Upon examening the switchbox, a decoupling cap to ground proved open circuit.

Switchbox+common mode filter(blurry pic). Mark-IV version of K9AY switchbox undergoing repair. The shack of PI4TUE, being the student clubstation of the Eindhoven Technical University (ESRAC), certainly had lots of spare parts available. At T-30 or so, the K9AY showed a F/B performance of several s-units on some european stations. That's good , right?

Available antennas

40m+80m dipole at 65mtr AGL
SteppIR yagi at 75mtr AGL
HF2V vertical for 40m/80m at 60mtr AGL
2x 0.25 wave 160m sloper at 65mtr AGL, direction USA and JA
K9AY at ground level

Contesting

Mark/PA5MW and Rens/PA3FGA during the night shift. Yes that's a 'capo', and a real one!

The new SteppIR performed very well; especially the bi-directional option was appreciated much.
Rens' Elecraft K3 #371(?) performed as expected; great RX on both main and sub-receiver. However, it showed some minor quircks: VFO A/B dropping out of sync, occasional strange offsets and during the first night a total backup reset via RS232 was neccessary to get it going again. Oh well... the firmware is still maturing and I have seen great devellopements during the last 12 months.
Operation-wise it's not my cup of tea. The Orion is a better (contest) rig; it offers far better manual control and view of all current settings. Next the Orion's antenna and VFO distribution and controls are clear and versatile. For me it sucks on the K3. We have been discussing several days on how to setup the K3 for true diversity and being able to switch back to "normal L+R" reception of RX or TX antenna's, without having to use more than a single button and certainly not having to enter (audio)menu's. On thursday I found a schematic on how to switch in/out from true diversity RX on both L+R ears, using an outboard antenna splitter on the K3 main and aux antenna inputs. This was cleverly designed by Bill W4ZV, who used to have an.......Orion :).

Ground connection on back of Elecraft K3 + common mode filters.
Next; one operator in desperate need for another espresso!

The David Clark headphones sure help in the noisy environment; since the PI4TUE shack also accomodates many local 2m/70cm/23cm/13cm FM repeaters, packet nodes, packet &psk31 links and zillions of network computers.

160m RX antenna performance at PI4TUE, or ..... the lack of
We have to do some more experiments since none of the tried 160m rx antennas has offered better signal/noise than our TX quarter-wave slopers so far, including this one. Despite the shown local F/B it did not offer any dx at all.
Over the years we have tried:

- KAZ on the north rooftop @60mtr ASL
- Magnetic loop on rooftop @60mtr ASL
- K9AY on the north rooftop @60mtr ASL
- K9AY at ground level, 110m north of the large shack building, 30m from a low building
- 160m short vertical at ground level, 80m north of the building
- K9AY at ground level, 180m west of the large shack building, 20m from a low building

K9AY & 160m short vertical used copper ground stake 1m + buried copper radials

The PI4TUE shack building is about 60-70m high, has a full metal frame on the outside. It accomodates a full size TX/RX 0.25 sloper on the west (dir. USA) and NE(dir. JA) side.
The above mentioned K9AY and 160m short vertical have been used at several other locations in which they performed very well with the exact same coax lengths and hardware. Difference is that at PI4TUE the coax travels from ground level along the building, some 50mtrs upwards to the shack room, 40mtrs away from the west-TX sloper. This long vertical travel will certainly not help making any antenna quiet.
This contest weekend , again we suffered from a RF noise level on the K9AY that no dx was heard at all. Is it local man made noise from the university buildings? The city environment? We will do a comparison measurement soon on a very short vertical, both at the university area as well as in one of our domestic field locations using a spectrum analyzer.
Both the TX slopers offer some reasonable F/B, thanks to the metal framework of the building. As such it was the best rx-antenna currently available.

Food, beverages, couch for crushing...

The next-door 'living room' with eat & sleep accomodations.
And Rens making true espresso or capuchino using Diemme ..something? I will do a seperate blog on his barrista qualities soon !

Operators
In no particular order: Aurelio/PC5A, Sjoerd/PA0SHY, Harry/PE2HD, Frank/ON9CC, Rens/PA3FGA, Mark/PA5MW.
And those who helped on friday afternoon/evening: Claudia, Steef/PA0IB, PA4A

From L to R: Aurelio, Sjoerd, Harry, Sam.

Was it fun?
Yes, it was fun as ever, being with hamradio friends together and contesting. 40 mtrs was just a-m-a-z-i-n-g. We need to pick up this momentum and go for the next contests in Q1 2009: CQWW160mCW, PACC, ARRL DX CW and ARRL DX SSB.

Summary:
Band  QSOs  Zones  Countries
------------------------------
 160:  299    14       56
  80:  496    20       80
  40:  655    33      117
  20:  919    34      115
  15:  241    24       66
  10:    0     0        0
------------------------------
Total: 2610   125      434  Total Score = 2,855,931

Despite only having a single "3-bander"yagi , some dipoles, slopers and verticals, being at +60m AGL does help. It is a privilege to use the schack and living room. Thanks to Sjoerd/PA0SHY, Steef/PA0IB and Martin/PA3DSC for their efforts they put in building/maintaining the PI4TUE/PI5HEV university clubstation.

untill the next one...

Give me a reason NOT to buy;

2008-11-16T15:46:00.008+01:00

dynamite, a gun, barbed wire etc....
Possession is all strictly prohibited in our country.
All for many good reasons. But after our latest 'experience', reason is a bit lost here.
Oh well.... get over it !

Above picture shows the result of our burglar visit.

What happened?
02:30 AM; I wake up because of a crackling loud sound. I switch on a bedroom light and go downstairs to the living room. There I find nothing abnormal; all doors are correctly locked, all windows seem OK. So back to bed again. I sleep quickly, so QSY zzzzz...
02:45 AM; again this loud noise. Instead of going downstairs, I put aside the window curtain, look downside left at my parking lot.....to see a guy in total black tight clothing, hand gloves and baseball cap. Upon detection he winks his fellow man and both run away quickly. There's an attempted burglary going on.
I jump into my hobby overalls, put on a pair of sneekers, open my front door and run into the direction they went off. I spent some 7 minutes looking at several cars, checking alleys and several roads.
It is not my intention to force a confrontation being alone without any arms whatsoever, but at least I want them to know that I do not just sit back and p*** my pants. And besides, I was being just a bit upset...

Burglar result
Using a 200m glass sucker, they tried to break the lock of the sash windows, which are on the side of my house where the parking lot is. They needed several attempts before the plastic window-chassis broke.
Only one lock of the outer windows is broken before they were detected while performing their profession.
No other damages have been found.

Police assistance
I call the alarm number at 02:55 AM and report the attempted burglary. At 03:30 they arrive, look at the window and enter my house to write a report. Upon their leave I ask if there have been any other attempts recently in my area; "no, not that we would know".
Later that day,I'm visited by two officers of the forensic research who take prints of the glass sucker and a hand glove on the second inner window.

Property owner action
Since I never open these windows, I decide to fixate the window permanently using glue. Next, I have cut some 25x25mm bars to block the windows:

More protection is needed; a Halogen floodlight with motion detector is mounted on the bottom of my antenna tower. It switches in after dark automatically.

The back fence can use an upgrade too; so I add a new layer of treated plywood. The most vulnerable part is done first. Next week I will do the rest.

Next to installing extra safety-locks, there are some more tricks&tips I will
be implementing this week.

Neighbourhood monitoring
A quick check at the closest neigbours revealed that there was a succesfully burglary 6 doors away, just the other week. Talking to these people and others across the street I learned that 2 more houses in our area have been victims last month. Would have been nice if there had been a short informing letter to everyone. Let's start doing that ourselves.

With regard to possible psychological effects
I experience no anger, extreme frustration or other negative effects. In fact I went to bed again 30minutes after the police left the house that morning. But I do understand very well that such might show up sometime. For now let's just say that at this point I regard the whole story a 'negative business encounter'; they want something from me, I want to avoid that deal as much as possible. I need to put more effort in my work there.
The story is different for my girlfriend though. Thank god she slept through the whole story. But she's seeing burglars everywhere and she hasn't slept well ever since. I'm doing my best to bring back that comfort to her.
Let's end this with the simple fact that there are other more serious issues in life and we will grow over this too.

If you have any tips or remarks, please feel free to add any comment

New omnidirectional verticals for 145 and 430 Mhz

2008-11-02T11:34:00.008+01:00

The Half Wave Sleeve Antenna
This model acts similar to the typical J-pole designs; a 0.5 wave radiator plus a 0.25 matching section. However, the coaxial pipe or sleeve section in this antenna has a much better choking action. This should keep the coax free from radiating and result in a better radiation pattern. In theory that is.
The popular J-pole is easier to construct, but the brutal feeding of the (unbalanced)coax to the (balanced)matching section is questionable. But there are new, better variations of the J-pole.
And let's not forget; both offer plenty of fun as they are very efficient antenna's.

Bad alternative; the commercial 'collinear' dual-band vertical
OK, I admit; I have used these typical white fiberglass collinear constructions for years. Everyone has (had) one right? It is by far the most succesful commercial antenna for VHF/UHF. Offers plenty of QSO's too, nothing to bash about that. I still have a 'short' Comet GP3 VHF/UHF for portable use.
But as soon as SWR acts funny you start investigating what this antenna is all about.
What I do not like:
- collinear sections, having no true stacking distance, do not offer the "theoretically calculated" gain. Funkamateur magazine did a comparison between a single rod 5/8 home made antenna and various commercial collinear antenna's back in 2005. Even the super 3x 5/8 (5mtr high) offered no more than some 2 dB gain.....
- bad connection joints "offer" a variation in SWR in due time
- capacitor failure in the bottom section
- 3 metal spokes function as 'groundplane'
When opening up such antenna you find pieces of welding copper, matching coils and small ceramic caps.

The Sperrtopf (german) or Fietspomp (dutch) antenna
Actually this sleeve antenna was designed by A.B. Baily and described in u.s. patent #2184729 in 1937.
The german word 'Sperrtopf' refers to its coax sleeve section.
The dutch word 'Fietspomp' refers to what it looks like; a cycle-pump. I always found them very ugly to look at, but this is not about cosmetics but performance & durability.
You can find some more info on how to build your own at: http://www.timroberts-vk4yeh.id.au/downloads/sleeveantenna.pdf

The 438-470Mhz Sirtel CX400D
I bought 2 of these a few years ago on a flea market. There's already one on my roof, see my blog of feb 24th.

To get them to resonate correctly in our 70cm UHF band section, I need to lengthen the radiator by about 6cm, or was it 8cm? Darn! Why do I forget to write down such evident info? My antenna analyzer stops at 30MHz. Well, l know someone who has an HP network analyzer AND makes great coffee. I will do a separate blog on his Barrista qualities soon :)

See above a really pathetic attempt to measure and adjust the radiator length. Surely the HT batterypack was near empty. And so was the reserve pack.
Let's finish this blog quickly and go to that coffee....

The Wimo 145MHz version
www.wimo.de offers a finished version at an extremely cheap price.
I pop-riveted the short alum mounting section to a clamp. A few layers of spray paint should ensure weather durability. The horizontal tube section is meant for creating a distance from my antenna tower, in order to get the best omni pattern. Mind you; I cannot mount this antenna on the top of the tower. Local restrictions do not allow this. Long story, let's not go there.
It is all about maximizing efficiency and setting priorities.

Where was I ?
Ah, time to get me that coffee :)

SteppIR @ PI4TUE - Part III

2008-10-26T13:11:00.015+01:00

The final day of this project.
Me and my XYL went to her family during the whole weekend, so again I was not able to join in. I had a great time in former Y22-country; enjoyed the superb hospitality, played with the kids of her sister etc.... Life is good, even without antennas.

Preparation for the last steps
More helpfull hands, safety tools, helmets, first-aid kit, everything to make this day a succes.
Again, you absolutely need perfect weather to work on a building roof at 220ft level. This turned out to be a beautifull day.

- Steef/PA0IB, Rens/PA3FGA, Aurelio/PC5A (wrapped in climbing gear)
- Assembling the prepared boom parts

- Tram trolley and protection against the existing guying wires by covering them with lengths of used plastic hoses.
- Steef/PA0IB assembling the control wires

- 6mtr add-on optional element
- Truss wire, not a luxury at such a height.

- 'Partly beam' just hoisted up in the air
- First-aid chick on standby
- Mind you; this is a small platform he is sitting on

- Lunchtime in the living room/kitchen/ contest sleeping room of the club station ESRAC at the 13th floor of the Technical University of Eindhoven
- L to R: Rens, Aurelio, Claudia, Steef

- adding elements
- "Look ma, no hands"

And then there's Murphy
OK, so what's different in the above second picture ?
The ground crew noticed a loose screw on the boom clamp of one of the reflector 'EHM' units. These had been loosened before to install the boom truss wire. Holy crap...!
So the whole ^%@## yagi had to be lowered again....
It is at this point that physical stress turned into overload as happened to Aurelio; suddenly his forearm muscles simply blocked and next his fingers were cramped-locked together. He got down and Rens took over.

- Switch of tower-operator
- Steef finalizing the control cable on the new Emotator FX1200 rotor

- On the left: HF-2V 40/80m vertical (not visual)
- SteppIR 3 el Yagi
- VHF antenna mast, including full size 40 and 80mtr dipoles
- Crossing the street-light; 160mtr sloper wire, barely visual

This final job lasted the whole day. Totally exhausted they left the premises at 18:00
During the week the antenna tested successfully ! This new antenna will certainly bring some new momentum in the coming contests.
In the meantime I have seen the antenna from ground level, it looks intimidating.

Again a job done very well guys !

SteppIR @ PI4TUE - Part II

2008-10-05T17:53:00.010+02:00

Last weekend the 'next step'was taken in this project:

Remove the old antenna's from the mast on the roof
The picture below shows the roof of the building at the Technical University of Eindhoven. Not all antenna's belong to the contest station PI4TUE. There's plenty of antennas for FM repeater and packet and other digi-stuff as well.

Safety first ! Especially at a total height of more than 70mtrs above ground level (230ft). We have had to cancel several saturday options because of fierce weather (wind).
The top antenna is, sorry used to be a 5 element yagi for 50Mhz. The front boom part +director was already dissappeared; it simply must have snapped off at one point. The wind forces can be huge at this height.
The antenna below is a classic old Fritzel FB33 tribander + extra WARC dipole (12-17-30mtr).

This is Aurelio, PC5A, being happy as the weather is such nice for a change :)
Blueman +white helmet is Rens, PA3FGA.
The tribander came down easy, well too easily for one end-part of a director as it came lose and just dropped down. Nothing was hurt or damaged though. Upon close inspection several bad or loose mechanical/electrical joints were noticed. Now maybe this explaines the sometimes erratic SWR behavior we have experienced ?

See how the boom has bended over the years?

Time for a well deserved pause and some coffee.
The room is situated on the top floor and adjacent to the shack of PI4TUE. It has facilitations for making thee/coffee, has a fridge and besides the 'diner-table' lots of room to relax on one of the old couches.
From left to right: Aurelio, Claudia and Rens.
I'm pretty d*** sure the beer is a "leftover" from some other group !!

Next the Emotator rotor was removed. Its internal slip-coupling is totally worn out. A previous custom modification lasted for another year or so, and now it is in-operatable again. This one simply has served its time. Pity that the custom mounting plate for the mast was corroded and stuck. This will be a job for others now. So the new rotor will have to wait. Too bad, now the project is on halt again. Oh well, it will be quickly dark and cold soon after such a day of hard work.

This is how much space the new SteppIR will take up. The try-out of the assembly was done to prepare us for the future final installation. It is convenient working with these"pro's" who make optimal use of their time available at that day.
Why I am not in any picture?
I was doing shopping with my YL in Amsterdam.

Job well done, much appreciated guys :))

Upgrade vertical polarized yagi for FM repeater reception

2008-10-05T15:57:00.013+02:00

Previously I have mentioned that I do like DX'ing on FM repeaters on 145MHz .
Not only both my transceivers have been specially upgraded for this (customized 455Khz filtering), but there is a dedicated vertical yagi antenna for this too. It is fixed at about QTF 160 in which I can constantly work PI3ZLB near the Belgium/German border on 145.725. During ducting propagation I can work, or at least hear other repeaters on that same frequency from Belgium, Germany and Luxembourg:

Repeater Near city Locator QTF QRB
PI3ZLB Geleen JO20WX 153 78km
ON0NR Namur JO20KJ 195 139km
LX0HI Bourscheid JN39AV 166 196km
DB0ZK Koblenz JO30SH 133 209km

The above vertical yagi antenna has been in use for more than 5 years now at different locations. It is a 4el '50 Ohm' direct feed version. The boom has been extended as the tower had a strong negative influence on the SWR. After the extension it worked much better.
Since I am planning an overhaul on my whole antenna system, this one needs some attention too. And while we're there, let's take it to the 'next level' right?

Old Flexa yagi's
At my old QTH I had a stack 2x 9el Flexa yagis's installed on my roof :

These were used for comparison to a single yagi having double boom length at the same height, mounted on a second mast. Total stacking gain was similar to the single long boom yagi, but the performance was slightly less. The wider horizontal angle(better for contesting though) showed more background noise.
My current location does not allow for a second tower/mast unfortunately :(
So both 9el Flexa yagi's have been lying around doing nothing ever since, actually rotting in the rain:

For those of you who wonder if these Flexa yagi's elements ( 2mm steel whip elements on extreme lightweight alumn) corrode on the element to boom contact, see below:

After 8 years of use this looks pretty corroded to me.

Rebuild to 5 el. FM vertical yagi
I decided to cannibalize one of them and rework it into a 5 element vertical yagi with offset mounting.
Time to do some serious cleaining & polishing :).
I just cut the boom and mounted the first 5 elements of this 9el design only. SWR measurements showed right what was expected.
Next, the boom required an extension for both the offset mounting bracket and the required extra distance from the tower.
I planned to insert a piece of the right alumn tube for the connection between the two boom pieces. The first few cm's go easy, but after that it's a tough job. The alumn insertion tube quickly grinds to a final stop. For durability I was planning to mount a parallel piece of boom anyhow, so after a sunday's afternoons job we get the following result:

Flexa yagi's have received a lot of critical remarks in the past about the (too) thin 2mm dia precious steel elements. I don't care about the 0.5dB discussions, all I see is its current merits:

Extreme light weight
Visual unobtrusive
Low wind load
Thick, high impedance dipole + balun

Can't wait to get this one it up in the air :)

Getting some of those 'small projects' done- Part II

2008-09-21T18:43:00.008+02:00

With the local weather being such good during the evenings, I managed to do a lot this week:

Entry panel

Added a second coax relay
Mounted DCI 145-2H 4-pole cavity bandfilter
All wired & tested

I'm now able to switch 3 VHF antennas (stack of 2x 4el horizontal, 4 el vertical yagi, vertical omni) to 2 different multi-mode VHF transceivers. The DCI bandfilter can be switched in on the omni-directional vertical. It is for experimental purposes only.
This filter was used at my old QTH were the IC-746 suffered from heavy IMD (receiver is wide open from 60-200MHz). A local low power 100.7 MHz FM BC station always was audible in the background throughout the whole 2mtr band, in AM modulation :). Next there were several near-by hams which added up to the to total 'distortion' picture.
At my current location I'm only using multi-mode transceivers which have decent bandfiltering in their front-ends, starting before the internal pre-amp. There seem to be no strong local signals, both in and out-band here at my new QTH. After several days of testing I simply cannot detect any difference with or without the filter, besides the small extra loss.

Exchange the rotor of the FM broadcast antenna setup
The old Channel Master 3-wire controlled rotor (1970's) was removed. It was never in sync with the controller, which in turn also got stuck on several occasions.
From a local ham I bought a Yaesu G-250 in mint shape. This is exactly what is needed; a simple light-weight reliable rotor for a small antenna setup. One minor issue; the brackets can only accomodate 38mm max. The current mast is 50mm and stuck forever on its mounting plate. Now being a ham for some years, you have lotsa alumn lying around right? I cut a piece from a 32mm tube and pop-riveted that to the 50mm mast on the roof. The FM BC antenna is build from 40mm PVC so no worries there.

This certainly looks much better than the ancient 70's rotor (see previous blog 29th april).
Black 'Body Protection' car-paint was used to weather proof some parts and darken shiny obtrusive parts.

New 1:1 balun for the 160m 'reference vertical'
This was on the list for some time; check the resonance adjustment of this reference antenna (see blog of 18th january), change the balun, clean and weather proof the connection box. The annual check-up. The old balun was a quick&dirty home made version.
The new balun was made from 2 binocular ferrite type #73, glued together and fixed with shrinking tube.
Two sets of each 3 turns teflon coated wire. One set was packed in an extra separate teflon tube.

In the connection box you see in the left upper corner the series resonance coil on a FT114-61 ferrite core.
Each winding shifts resonance about 25KHz. Resonance was set at 1825. Bandwidth is about 25-30KHz (SWR=2). Antenna impedance at Xs=0 still remains at 50 Ohms, which shows my ground system is not sufficient. Bad luck, my garden just not allows for many radials of any decent length. I'll have to stick with the copper 3mtr 2mm dia ground rod and 4x 4mtr length buried radials.
There have not been any verification tests, besides the usual on 160m and the upper part MW BC. Theoratically the new balun should do be a better job in common mode rejection. In practice it surely looks 599.

The winter low-band season has already started.

Now what about:
- that phased vertical system?
- a 'TX' antenna for a change?

Top loading on 7Mhz vertical

2008-09-14T22:07:00.018+02:00

Just to kill a free sunday afternoon we decided to do some experiments with toploading on a vertical in the backyard of a local ham.
We wanted to acquire some practical experience on this subject in case we will need this for any future fieldday style setup.

Starting point: a 7.025 Mhz vertical 0.25 length, downsized to 65%
Using 2.5mm2 copper wire (about AWG13), a vertical wire was taped to a 6.5mtr (21ft)fibre glass rod. A top-hat was fabricated from the same copper wire, soldering 8 spokes on a round piece of circuit board.

Result: 8 spokes 0.55m => 7.95 MHz
Next a series coil was installed at 1m70 height (5.5ft) to lower the resonance to the wanted CW band portion (7.025Mhz). This required 12 windings with about 7cm diameter.

Going from 8 to 16 spokes
Not being satisfied with the series coil we removed it and decided to start enlarging the top capacitance loading.

Result: 16 spokes 0.55m => 7.41 MHz
That's a 7% change, more than 500Khz. Nice but not there yet.

Adding a ring on the top hat
A single ring was soldered on the 16 spokes. This created a far more rigid construction.

Result: + ring => 7.35 Mhz

Hmm...bit of a dissapointment here.
There's no room for additional spokes on the copper mounting plate so let's try lengthening the spokes.

16 spokes + ring + 0.3m extra length on just 4 spokes
Enough bare copper wire available so let's "solder-glue" some extra length on just 4 spokes.

Result: 0.3m extra length on 4 spokes => 7.06 Mhz

Almost 300Khz down now. Close, but no cigar yet !

16 spokes + ring + 0.15m extra length on 8 spokes
The 4 spokes look silly, right?
Now how about lengthening 8 spokes with just 0.15m? Will 8x 0.15m be the same as 4x 0.3m ?

Result: 0.15m extra length on 8 spokes => 7.12 Mhz
Nope; this is a small step backwards. But at least we get confirmed what works best.

Final option: 16 spokes + ring + 0.15m extra length on 12 spokes
OK, just add a few more extra lengths...

Result: 0.15m extra length on 12 spokes => 7.02 Mhz
Bandwidth is 350 KHz at SWR 1,5

*Ding* we're finally there.........

Oh .. wait his XYL comes home and looks up in the sky: "What a nice sun-flower you boys have created".

Eeehhrm.......???

Time for some coffee :))

Getting some of those 'small projects' done

2008-08-30T10:15:00.014+02:00

Ham radio operators keep upgrading their equipment, shack, antennas etc..
You visit a flea market and pick-up those things which 'you will surely use sometime in the near future'. You're at the beach dozing away in the sun, but your mind is fantasizing about new 'projects' to build at home. Your workbench is filled with all kinds of parts & stuff. You visit a ham friend and while having coffee, he shows you his 'latest project'. You're thrilled and his activities immediately hit you; there are zillion unfinished/non-started projects at home.

Make a list and prioritize ?
Well that's how I usually work; I make a long list of all what comes to my mind and then start thinking about how likely is it that such a project will end successfully, how long does it take, what does it cost, how does it affect the current situation or other future projects, does it really help me, how badly do I need it? etc..etc..
At my QRL we call this doing a feasibility study.

Since I'm not at work I thought it would be best to just start with something small and see where it all ends, right ? :))

Mains filtering

These are industrial parts which create a 500V/40A mains filter. I should probably need to add a kind of protection cover, but at this point it physically is already out of reach....

And while we're at it, take a look at my mains common mode filter. I have these installed at every power supply and any mains cable power block. This nickel-zinc-ferrite has a permeability of 1500 and has wide band coverage from low HF to UHF. It is available at: http://www.dx-wire.de partno: U81-1500
It is 60mm long and allows for 10mm dia windings. 9 windings should bring already >1000 Ohms @3Mhz, which is very good.
I have never been able yet to measure any difference before and after, but its brute visual placebo effect certainly creates some dB's.

The already forgotten Elecraft noise generator kit appeared under a pile of paperwork and was completed in half an hour. It generates noise from DC into UHF and will serve me well when doing HF RX alignment in the future.

The outdoor antenna coax switch
I am using a 2 way remote coax switch up in my roof tower. But in order to activate it, I have to crawl under my operating bench, find that DC control wire and connect it to a 13.8V PSU.
A 'switch board' on my desk would be nice. Since I have plans to add more antennas, more remote switches for both antennas and rigs, this project was taken a bit more seriously.
Then there's the outdoor switch box for my HF Lowband RX antennas. Both the switch box and cable is already installed outdoors. It only needs some connection +control in the shack... Oh well let's take it one step at a time but keep in mind what else will come next soon.

The entry panel
This panel will cover:

DC wiring for remote switching
DC wiring for rotor
DC wiring for HF Lowband RX antenna switchbox
Central ground point connection
DCI 144-146 4 pole cavity filter
Various coaxial relay switching
Coax entry connection strip

The Dowkey Microwave coax relay is a 12GHz type, which provides 85dB isolation at 1 Ghz.

Next we need a control box. So look into the junk box for switches and dig out any plastic box from the supply cabinet.

The wiring was done with some junk CAT4 cable and RG174 for DC supply +more placebo's.
However, the Dowkey relay uses 28V. I tried using three 9V batteries in series but those lasted only a couple of hours. I located a non-used 12V/2A power supply which has 24VDC at the rectifying stage. It was quickly modified; just added a few zener diodes in series at the GND leg of the 7812 voltage regulator to bring it up to 21V (leave some room for operating DC offset for the regulator). The Dowkey relay already works from 13V up, so the 21V is within 'my' specification.

How does it all work so far ?
Very well.
I can switch between 3 VHF antennas and 2 multi mode rigs.
Both on sensitivity, selectivity and AGC behaviour I see interesting differences between the IC821H and TS790E (note: they are not in original state; both have there IF FM filters modified and are realigned. See my previous blogs).
The newly added versatility allows for more fun in the shack!

What next?

install the second relay and wire the DCI 4-pole 2m filter
.........

Simple HF Multiband Vertical ; Part II, the home Stealth version

2008-08-24T21:10:00.008+02:00

NCDXF HF Beacon Monitoring

For several years now I'm using VE3SUN's computer program "Beacon Observer".
See: http://www.ncdxf.org/Beacon/Abeacon/BeaconObserver.html
This is a very informing tool to monitor the NCDXF HF beacons. I like it better than Faros.
Via RS232 it controls your receiver, switching between all upper 5 HF bands from 20 to 10mtrs.
In 3 minutes you have a graphical overview of all world-wide 18 NCDXF HF beacons per band, which each operate in a timed sequence for 10 sec. 18 beacons * 10s * 5 bands= 15minutes for a total overview.
This kind of monitoring shows band propagation 24/7 and during the year the several seasonal propagation changes which are huge.
There are numerous band openings which happen when we are away from our shack. Ever seen the typical Es night openings on 10mtrs? Well there have been many this summer! After an evening Es opening, usually every 3-4 hours later there's are more. That also goes for 50Mhz and was proven this summer during our HB0-holiday trip as the only USA qso's I have made on 6m where at 01:30 local time....
Anyway, I will spend another blog about my NCDXF HF monitoring system in more detail in the near future.

Stealth antenna

Receiving these HF beacons requires a multiband omnidirectional antenna.
In order to minimize the visibility of any 'vertical hardware' I have built a multiband fibre glass rod vertical according the earlier written basics and put it between the branches of a near-dead tree at the boundary of my garden. Some non-glossy black and green spray paint has made it unobtrusive for non-hams.
However 3 issues made it impossible to tune it correctly for all 5 bands:the heavy coupling between radiators, elevated radials which doubled the adjustment issues and the accessibility in the tree.
Now, you could suggest to make a temporary setup in the clear in the middle of the garden so you can lower the antenna quick&easy for adjustments. Mind you, this is not a true (on-) 'groundplane', but 'elevated parallel radiators and radials' which makes tuning a critical task. And it behaves different when you move its location.
For RX-only good SWR is not a requirement, it just needs to receive well.
My design has evolved in an MK-II version over time. Its MTBF was pretty low. Some radiators got tangled up due to heavy wind. The radials got accidently cut while gardening. Next the cheap&easy connection hardware corroded, despite anti-corrosion spray and stuff.

A good reason for building a newer, even better version every 1-2 years. After all; there's nothing like building a new antenna :)

Can you spot the antenna?

The MK III version
The most important lesson learned during building our multiband verticals in the field is that the vertical radiators need enough space between them to avoid those coupling effects. Especially at the bottom/feeding point.
Some specifications of this new version:

Radiators are spaced 30cm from the central fibreglass rod
5 radiators adjusted for 14.100/18.110/21.150/24.930/28.200 Mhz
0.5mm, non-stranded, tinned, isolated hookup-wire (Conrad #211169)
Current balun; 7 bifilar windings on F-150A-K core
Electrical connections twisted and soldered
All heavily coated by multi layers of vulcanizing tape
Some more non-glossy black & green paint spray

Using my Palstar Antenna analyzer and its supplied 1:1 balun, the adjustment went pretty well. Radials had to be disconnected often, to prove if they behaved as wanted.

How does it perform ?

Slightly more HF output, but more important: it is constant over the 5 bands. I'm not using the pre-amp on any band any more now, the (earlier modified) TS570SG shows enough sensitivity.

Any wishes left?

No. Let's wait and see for a few years before I start thinking of MK III.....

Simple HF multiband vertical

2008-08-09T07:54:00.016+02:00

Your own HF multiband vertical

During my first participation in the annual HB0-PI4TUE mountain dx-peditions back in 2003, I found that by using a fishing pole and some wire, you could build a very simple quarter wave vertical. Just tape a vertical wire along some fibre pole, throw a few wire radials in the bushes and go for it. Adding a second vertical wire in parallel made it a multiband antenna. This newcomer's antenna was a bit mistrusted at first, against all other vertical aluminium on the premises.
But it soon proved very competetive. The other commercial trapped vertical, showed not only signal loss, but were more noisy on reception. From then on everyone wanted to use this 'new kid on the block' and the 'trapper' soon became the 'lone black sheep'.

From that summer onwards we started playing with the concept at thome and during field day set-ups. We wanted more bands along a single fibre rod, so why not make a 10-12-15-17-20mtr vertical using 5 vertical wires?
In order to avoid coupling between the radiators we used spreaders to keep them separated from the main rod. Many attempts and numerous antenna measurements using various analysers proved; mutual coupling is-a-big-deal. When we thought we finally had concord the animal we took our new 5-band design to the mountain the next summer. Up there it took 2 days to get the thing working..... :(

Some don't s on multiband verticals:
- anything closer spaced than about 30cm (1 foot) is prone to cause heavy coupling
- too many bands will not work; forget about 40-30-20-17-15-12-10
- not using a balun/common mode filter makes the coax just another disturbing radiator
- elevated radials double the trouble of coupling and adjustments
- do not expect that the ground radials act similar in another location
- do not expect that it will be reliable and still have the same SWR after some rain and/or wind

If you have plenty of time and patience, a lot is possible. You will notice that for a single frequency it will 'jump between radiators' and the same goes even more for elevated radials. You have to connect/disconnect wires every time to verify which radiator/radial is dominant. For a field day style setup another approach is required. After trying many designs, we now have some reliable repeatable ground rules.

Basics of the multiband quarter wave wire-vertical

Note: this is a tribander for 20-30-40mtrs

Vertical: 12mtr/40ft fibre pole
Wire: anything will do, start with a length just over 0.25 lambda
Spreaders: plastic about 60cm/2ft long. Used on both top and bottom
Radials: minimal 8 laid on the ground, either straight or in zig-zag shape
1:1 Balun: use any decent common mode choke (not in drawing)
Adjustment: start from the lowest frequency upwards

Since the rocky bottom and many plants/bushes on our mountain do not allow for many straight radials, we opted for 8 radials laid out in zig-zag shape. Each corner was fixed uding an iron nail. This created plenty coverage of copper nearby the radiator and is accepted to perform better as fewer longer radials. See also "Lowband DXíng" by John Devoldere ON4UN, or "Monopolantennen und Vertikalantennen" by Gerd Janzen.

First vertical; 12mtr/40ft fibre rod

Above vertical resembles the design in the drawing. It has 3 radiators for 20-30-40mtr band
A current balun was used with a toroidal core type FT240-K.
A 1mtr length copper tube was hammered down and served as ground radial connection.

BONUS:
- the 30mtr radiator length is close to 0.75 wavelength on 10mtrs.
- the 40mtr radiator length is exact 1.5 wavelength on 15m.
Both showed a good SWR pattern. It performed very well on 10 and 15m where the typical high angle lobes proved worthy during the rare european Es openings .

Second vertical; 6mtr/20ft fibre rod

This uses the same basic design, but has 5 radiators

Above vertical has radiators for 10-12-15-17-20mtr band.
The current balun uses a toroidal core type FT240-67.
A 1mtr length copper tube was hammered down and served as ground radial connection.
The small blue box is the clue for a former blog entry :)

Performance
Both antennas were pretty quickly setup. The minor adjustment changes were due to different ground environment from home.

Using these two multiband antennas we have made some 5500 contacts. They both perfomed very well. During the IARU contest we managed to make >800 qso's in an 18hour effort.
Operators found the antenna very competeteive on 40mtrs where we could run a frequency without problems every time we wanted.

Think about it; your domestic situation certainly allows for any this kind of antenna.
And its a full size performer, not to mention cheap !

Peurto Rico on 6m with 15W output only !

2008-08-08T22:05:00.000+02:00

The Icom 746 has been returned to its owner.
It's already end of the ES season, so only a noisy band right?
All of a sudden the cluster yells that WP3UX is loud on six. Now I have already worked 2 KP4's this season, but hey 'it tickles'.. catch my drift?

I do have an Elecraft K2 and the 50MHz transverter (XV50). After juggling with some coax spaghetti behind the desk I'm in hunting mode. Darn, he is LOUD !!!
Willem is working europeans in true contest style. I cannot get through though, having only the transverter and no PA.
After some 30min I finally manage to get through when he is peaking S9 on the K2 (pre-amp off).
Willem mentions that there are zillions of EU-stations coming in and he is using 400W against my 15 :))

Aurelio, PC5A who I was in contact with on 145MHz hears this conversations too. I convince him to try it as well; within 2 minutes Aurelio makes it to Peurto Rico, using only a 1.5 mtrs whip on his balcony !!!

This evening I worked GD, GW and 7X (new one !) which brings my cty total up to 56 for 2008.

So it is a true magic band after all......

What are those two hams doing exactly?

2008-08-08T21:39:00.002+02:00

OK let's make a contest out of this; what's going on here..........???

I wonder who guesses this right :))

17 Beautiful Summer Holidays in HB0

2008-08-05T21:14:00.020+02:00

We're back home again !

We have spent some very nice weeks in Liechtenstein. Enjoyed the great scenery, had delicious meals, walked the mountains, listened to music, slept day and night, build antennas, completely build a K2, played hamradio operator, or just did nothing particular at all :).

Some very nice moments are engraved in our memories.

Where did we go exactly?

Location: Bergstation Sareiserjoch (2000mtr ASL)
City: Malbun (1600mtr ASL)
Country: Liechtenstein

See their website: www.sareis.li
Or check the webcam: http://livecam.feratel.at/cam/malbun/4135/index.jsp

So how did our newly build 7 el/50MHz yagi do?

Building yagi's

First the old reliable 5el/50MHz was setup on the cabin's 15mtr alumn mast. It is a 4.5mtr boomlength DK7ZB design. Form left to right: Aurelio/PC5A, Rens/PA3FGA, Mark/PA5MW.

Next we installed a portable alumn mast on the top of our mountain. The mast was being completely rotated. This required a top support bearing and a rugged construction at the rocky bottom to fix the rotor.

After many blood, sweat and sunburn, the antenna was finally raised late in the evening.

The coaxial feedline consisted of 20mtrs Ecoflex 15 (15mm diameter) and some 30mtrs hardline (35mm) into the cabin shack. Despite all these extreme low loss cables the new 9mtrs boomlength 7el long yagi antenna(design PA3FGA) was almost dead quiet, especially when compared to the second 5el yagi. The smaller front lobe and carefully designed minimal side/backlobes offered a lethal point & shoot antenna.

The 6m shack consisted of (from left to right): Create RC5A-3 rotor for 7el yagi, N1MM on laptop, Icom IC-746 inc Inrad filters +some mods, CDE Rotor for the 5el yagi, David Clark stereo Headphone, Bencher CW paddle, Kenwood MC-60, home made XXXL footswitch for PTT. The dx-cluster information was supplied via our local Linux packetnode (see earlier message june 10th).

And did the 7el/50Mhz work?

Yes it did!
Besides seeming 'dead quiet' it simply offered great dx which could not or hardly be heard on the smaller 5el. Now that is no real A/B comparison since the 5el is near the cabin (man made noise) and some mtrs lower. Anyway, we were ashtonished by the performance of the big-beast (portable, mind you !).
Switching between both antenna's showed between 6 and 10 dB difference (what's in a number) according the stations we worked.
Weak (tropo) signal performance was simply stunning; almost every spot in Europe could be worked somehow whereas the smaller 5el showed nothing but noise.

Some statistics:
>620 QSO's on 50MHz
>50 countries

Callsigns used on 6m:
HB0/PC5A (op: Aurelio)
HB0/PA5MW (op: Mark)

Despite being near the end of the Es season we worked caribic stations like 9Y4, PJ2, KP4, KP3. We managed to get easy through the big EU pile-ups on first or second call. Some USA stations even have been worked during night hours. I worked dx I would only dream of at home. What a difference with all 50Mhz antennas we have tried there in the past!! Size does matter.

Bergstation Sareis, Malbun, LI. (HB0)
From left to right: weather monitoring station, 7el/9mtr 50MHz PA3FGA yagi, 5el/4.5mtr 50MHz DK7ZB yagi, 20mtr commercial mast for domestic emergency communication.

Thanks to all of you who worked us !

HB0-summer 2008 preparation; 50MHz 7el PA3FGA design

2008-07-06T13:31:00.012+02:00

Design 50MHz long-yagi by PA3FGA

From 7th july onwards PC5A, PA3FGA and PA5MW will be QRV from HB0 (www.sareis.li).
We have decided to use 2 different 50Mhz yagi's in order to maximize our performance; one 5el/5mtr boomlength DK7ZB design and a 7el/9mtr boomlength PA3FGA design.

Rens PA3FGA designed this long yagi, starting from a basic 7el/28Ohm DK7ZB version. He optimized the pattern, using a boom length of max 9mtr for reasons of transportation restrictions (max.3 mtr). The F/R specs have been optimized at only minor gain loss. See radiation plot.

Building the antenna

During these last 3 weeks Rens has been busy building this 'portable' 7el/9mtr(30 ft) boomlength long yagi. The whole package should be easy transportable on a car roof. However; Rens is not the kind of guy to produce just any 'temporary light- weight easy-to-go' construction. This meant balancing the various criteria, stretching all mechanical possibilities.

The single elements are mounted with help of customized 'perspex' plates which clamp on the boom.

Matching to the '28 Ohm' radiator is done via a 2x 1/4 wave 75 Ohm coax in parallel, according original DK7ZB design. Boxes are type IP66 and 100% waterproof.

The completed 30ft/9m antenna just fits in the backyard garden:

This is us, positioning the 28/50Ohm transformer section on the boom (PA3FGA, PA5MW).

Any practise results yet?
That is a defenitely no. We have no time left and just count on our luck ( and perhaps Murphy?).
There are still other things left to do before our departure tomorrow.

Meanwhile, while packing my stuff I managed to work from my shack:

6m today:
NP4A
PJ6/K2KW

earlier this week:
HI3TEJ
JX/G7VJR
UK9AA

HB0-summer 2008 preparation; IC746 alignment

2008-07-02T09:11:00.008+02:00

My holidays have finally started; spend time in the shack, do the garden and visit a barber.

Time to do the Icom 746 alignment

Goal: check/optimize receiver adjustments.
Some 5 years ago this rig has been upgraded with INRAD SSB and CW filters and the RX gain setting was changed.
The master LO is dead on 60Mhz, showing 8Hz offset. The Philips PM6615 frequency counter (incl txco) was calibrated >5yrs ago. It is within 10Hz from the Marconi 2955 which was calibrated when I bought it in Germany in......ooh well!

What settings were re-aligned?

- LPL VCO Lock voltage; level at 1.84V instead of 2.0V
- RX peak L241
- Receiver total gain; setting from '38' back to '32' (about 30deg. on the potm)

All other adjustments proved within specs.
The software menu adjustment procedure was skipped; s-meter settings and stuff do not make QSO's.
Hooked up the 746, just in time to work TO5E (st Barthelemy dx-pedition), COOL!
Pity my logging software(DXBase 2006) is so difficult to upgrade with new countries; already 3 not recognized: E7 Hercegovina, 4O3 Montenegro and the TO5.

Time to collect stuff from my garden-house:

From left to right:
- 5el +boom parts 6m DK7ZB home made yagi
- 10m fibreglass DJ6NI pole for K9AY setup
- 10m Alu mast (70mm bottom, 35mm top)
- Comet GP3 2m/70cm packet antenna
- Rotor cable
- 'Tool' to find clear HF frequency, manage pile-up etc. :)

Good propagation today on 6m!

This morning, while eating my cereals, I worked Man JL8GFB on 50095.5 He was in and out the noise but very LOUD. I touched him on a few occasions but due to QSB he copied my callsign only partly. With some patience I wkd him during his peak some 20 minutes later. Check out his breathtaking setup at:
http://air.ap.teacup.com/jl8gfb/

6m band is exploding today; zillions of signals calling asia and many other directions. Just wkd CN & CT3 which brings the country total at 46 for 2008.

HB0- summer 2008 preparation; IC746 Mods

2008-06-22T20:31:00.008+02:00

The Icom IC746 which we will use on 50Mhz during our trip to Liechtenstein (HB0) next july, needs some work:

Cleanup
IC151 modification
Master LO modification
Re-alignment

Cleanup
Yeah sure, but let's wait untill we return from our HB0 trip. If you can find the dials and read the screen you can make qso's right? Its a bit dusty, nothing to worry about now.

IC151 Modification
The IC-746 suffers from potential thermal failure of IC151 resulting in no RF output. During normal operation this ic dissipates some 250mW continuously, where it is rated at 330mW maximum @25deg C. Its tiny legs become the heatsink in practise.
See the small MMIC red marked in the lower left side.
5 pins (3 left and 2 on the right) are GND connections.

Just Google on IC151 and you will find many ways to rework this issue.
I found a small thin piece of copper which served as an internal cabinet ground contact of some other rig. After a small modification and carefull cleaning it was ready for its new job; act as a heatsink.
I resoldered all pins of IC151 and carefully soldered the copper plate to the 3 GND pins, making sure its flat bottom was seated against the cleaned topside.
At this moment I'm testing the rig and it works fine. After some 10min now I can feel that this copper plate gets warm, that means it acts as a heatsink. One job done.

The small solder 'flag' was removed after the picture.

Master LO Modification
The reference Oscillator has its crystal mounted in the middle of an open (!) metal cabinet.
Any quick temperature change (like during TX, when the large internal fan accellarates) will potentially result in a short-term frequency offset. Sure any (optional) TCXO will handle that, but there is a cheaper solution. Just stuff it with wadding from a first-aid kit. That is all.

Next......?
Alignment can better be done when more time is available and the rig & measuring equipment are warmed up properly.

HB0- summer 2008 preparation; Packet Link Setup

2008-06-12T22:37:00.010+02:00

Preparations for another summer trip to Liechtenstein (HB0) are runnning fine.

One of the things missing at our mountain top location on the "Sareiser Joch" in Malbun(www.sareis.li), is an internet connection. Disturbing how quickly you get used to that common luxury when it is not availably for a change. A Long, (very) long time ago we started with pen & paper log but got quickly spoiled by the DX option in N1MM logging program :)

In the past our group (HB0/PI4TUE) has always succesfully used a packet link, which provided dx cluster info and, entry to relevant convers chat channels. Unfortunately our packet-node mini laptop (toshiba Libretto) from Gert, PG5D died 2 yrs ago. We were desperately in need for a new setup.
Personally I very much dislike anything related to soft/hardware programming. But one great advantage in group dynamics is that there's always someone who does like this stuff and will go to the bottom to get such working.

What is needed for our local packet node setup?

Short 430 MHz Yagi Antenna
TRX with 9K6 capability (Kenwood TMD700)
Laptop with AX25 Packet Node on Debian Linux OS
Wifi Router/USB-Hub Philips

How to build your quick & dirty 430Mhz Short Yagi
Cannabalize an old UHF TV antenna and re-use its boom and mounting bracket.
Find some alumn pieces and cut them to the required lengths according a 9el design on DK7ZB's website. Next, cut some trespa pieces and 'pop' them together with the elements to the boom. Now use any water resistant(Class: IP65) wiring box from an electronics store for the dipole. The balun/impedeande transformer is made from 2 pieces 0.25 wavelength 75 Ohm coax.
All done in a saturdays afternoon. Can't be more simple than that, now can it?

The mast is a fibre type. At only 4mtrs height in the middle of a small village, it receives the packet provider PI1EHV on 430.925 at 22kms distance, loud enough for a probeabely solid AX25 connection.

Test setup
We're up and running! Nice to "hear" that vintage 9K6 noise data connection on the 70cm TRX again.
Compliments to Rens, PA3FGA who spent 3 weeks building & programming the whole setup including the antenna.

The dx-cluster runs on the above old laptop packet node on the left. From N1MM on the wirelless connected client laptop on the right, we can setup a packet link within seconds. Three different laptops have been tested simultaneously and work perfect.
I'm getting in that dx-pedition mood again :)

What is next?

Build a time server so all N1MM client laptops run the same system logging time
Rebuild the 5el 50Mhz DK7ZB yagi
Build a new 50MHZ long boom yagi ??
Rebuild and test the old K9AY
re-align the IC746 and do the IC151 mod
etc..etc..

Nostalgia; Radio & TV Broadcast Antennas

2008-06-10T13:54:00.006+02:00

Current summer weather does not allow for weekend HAM projects. Being that ”radio-nerd” doesn’t mean I do not actively enjoy sunshine and outdoors activities like sports. In fact I do and I care less about the missed opportunity to HK and JY on 6m these last few days (new ones so, do I really???).

Anyway, while swimming in Bückeburg (Germany) I noticed a typical classic german Radio& Television tower in the background. This kind of view brings back early memories of our summer holiday car travel to Switzerland, Italy or Austria, during which I spotted many of those Radio/TV towers along the german highway (Autobahn).

During the trip home we passed this one more closely while taking an alternative route(B65) to the Autobahn (A2). This Radio&TV tower is situated on top of the Jakobsberg near the city of Porta Westfalica. More detailed info on the geographical site and the tower can be found on:

http://de.wikipedia.org/wiki/Fernmeldeturm_Jakobsberg#Neuer_Fernmeldeturm

According this website: http://www.senderfotos.de/nrw.htm , the site is open for public. This 135m high tower can be visited at the first level (25mtrs). The two large surroundings are at 50 and 58m height.

Before the closing down analogue TV it served:
ZDF UHF ch 26/300KW
WDR UHF ch57/330KW
NDR UHF ch54/20KW
These analogue transmitters have been shutdown since may 2006, from which DVBT was started.

Today the tower serves:
95.7MHz FM "Radio westfalica"
WDR-Bouquet 1 UHF ch26/5KW
WDR-Bouquest 2 Bielefeld UHF ch31/5KW
ZDFmobil-Bouquet UHF ch33/5KW

Getting the most out of your rig; the TS570SG modification

2008-05-30T21:07:00.013+02:00

One is never satisfied....

Making that QSO on 50Mhz largely depends on being there at the right moment.
However, some rigs offer that tiny bit of extra performance which is sometimes needed to hear the other guy at all.

I always enjoyed the ergonomics and user interface of the TS-570SG. This medium sized rig is a joy to use and easy to carry during holidays. I use it already for two years now as my main 50Mhz rig.
In order to enhance its performance I opted for two modifications:

Exchange the std 2400Hz SSB filter for an Inrad 2100Hz
Add a temperature controlled crystal heater from Kühne Electronics (DB6NT)

Installing the SSB filter
The original Kenwood 2400 Hz (YK88S) is taken out and exchanged for the Inrad 2100Hz (#94).
The '2100' offers better sound quality thanks to a near optimal filter shape. Its bandwitdh is a perfect balance between the std. wide 2K4 and the thin sounding 1K8.

The TS-570 does have one optional filter slot, but that is already taken by a 400Hz Inrad CW filter.

The filter is installed upside down, using insulating material and hot glue.Two customized pieces of RG316 are been used to connect it to the pcb.

Installing the crystal heater

At http://www.kuhne-electronic.de/en/shop/155_Crystal_Heater
you will find all info on this 13 euro (only) product.
Just slide it on the crystal of your main LO and apply hot air to let the heath shrink tube do its job.

How does it perform?
I was able to make a qso with this S7 YU-station on 6m while another SV-station S9+20 was at only 1.5Khz above. Subjectively this is surely different from the past. But since I cannot do an A/B comparison this means ZILT. It only proves that the SV station had a clean signal.

Epilogue
I have been very active on 6m these last two weeks since Es propagation has just started.
I managed to work: I, 4X, SV, ON PA,UR,LZ, LX, DL,EA,CT,YO,LZ,YU, HA, OM, SP,4L, ES,OH,YL,EA8,ER,CU,IS,9H,EI,EA6
Inter-continental: KP4

Am I happy?

No, not entirely.
The TS570 still does not sound optimal. I know it suffers from some phase noise and this is shown by the fact that I have a hard time hearing the other station. It is buried in noise and garbage. The other stations are worked on first or second call with 100W. A soon as I can hear them I can work them easily. But on many occasions I cannot read their reply or report. Very frustrating. Changing settings on the rig does not help. Using the calibrated SSB Electronics masthead preamp doesn't help either.

Picked up an IC-746 with Inrad filters from a friend who does not use it. I have had such a rig in the past too; they are very very nice to operate at 50Mhz and 144. Within minutes during a hectic Es bandopening I'm on a roll; this is just wat is needed.
The Icom is in a different league. Both on reception quality and ergonomics it does for me what it takes on 6m; quick and versatile operating options. RX is better, now I can hear into the noise layers and hear dx at sub-consious level.

Wkd: V4, 8P9, TA, EA9, T9 (again 2 new countries :)

RX Audio Interface to your PC

2008-05-16T21:25:00.008+02:00

Whenever doing AF analysis with help of any audio spectrum analysing software at your pc, you're probably facing several interfacing issues:

50Hz hum
RF interference from various sources
Bad ground/ ground loops
gain/impedance mismatching

The first 3 are referred to as 'pin 1' issues in the world of professional audio. In one word, proper grounding architecture & shielding, or the lack of.
Mind you, the audio input on your sound card is usually already a disaster having bad or failing ground contacts. Next the pc has analogue and digital circuitry, there's a cable to your TRX and there it is susceptible to RF. Not to mention the many ground loops etc..

I have been successfully using Spectran, a freeware audio analyser programm by I2PHD and IK2CZL.
When the audio is directly linked to my sound card input you get the below result (volume settings at zero):

My sound card is an old 16bit Soundblaster compatible type. Any current 192KHz/24bit High-End sound card will lower the noise floor by some additional 10 -15db. For the required measurements this old 16bit card has proven to bemore than adequate.

How to get a 'clean picture'

Use properly shielded cable
Install an audio isolation transformer

To conquer the 'pin-1' issues I opted for an audio isolation transformer. These usually are 600 Ohm, which might introduce small mismatches. I terminated its output, added some RF filtering on the output and finally put it in a box with both 3.5mm Jack as well as std RCA in-/outputs:

With the RX Audio Interface inserted (as near at the sound card input as possible), you get the following result:

SteppIR @PI4TUE- part 1

2008-05-06T21:19:00.007+02:00

Last weekend we started building the SteppIR 3el yagi for our clubstation PI4TUE at the University of Eindhoven. On the above pic: on the right front Aurelio, PC5A, on the right back Rens, PA3FGA and me in the left corner.

First all parts are checked.

Glass fibre tubes are treated with rough sandpaper in order to create a better grip.

Boom and motor sections are ready & tested.

Next action:

Remove current Fritzel FB33 yagi from the roof (220ft AGL)
Install new SteppIR 3el yagi
Install new coax cable

That 'other' radio hobby...

2008-04-29T09:39:00.015+02:00

"FIRATO" at the RAI exposition in Amsterdam

From 1950 till 1998 the Amsterdam RAI exposition centre hosted the Firato every two years. This was a consumer electronics show, mainly focussing on Hi-Fi and TV&Video.
Several new introductions took place at the Firato, like:

1963: The second national Television Channel (NED 2)
1963: The Philips Compact Audio Cassette
1967: Colour television by Philips
1978: Text view by the BBC
1982: Compact Disc by Philips

From the 90's onwards, people slowly lost interest in Hi-Fi and TV/Video. Home computer slowly took over...
During the period 1978 till 1985 I had a great interest for Hi-Fi. Every show I dragged tons of folders and stuff :)
I have been drooling at the top models of Philips Hi-Fi equipment, which at that time were accordingly high priced. Definitely not in my league, not even with my saturday-job at the local gas-station. It was mainly Akai I could afford and which suited me very well.

From early 2006 onwards I have slowly started collecting some of those legacy Philips products.
Local Flea markets and internet are superb for this. Even E-bay is useful, as I have collected rare Philips products for only 25 euro. These beautiful products did cost some 700 euro, back in 1979.

Philips AM/FM tuner type 22AH105 and Amplifier type 22AH308

The second CD-player ever: CD300, a second '105'tuner and a receiver 22AH306.
There is more; like a record player and , and.....etc.

Short note: this is all in my shack. Not the living-room.

Dating from 1978; the 22AH794 receiver, accompanied by the '541' Motional Feedback active loudspeakers (1976).
I own several 'Philips MFB' loudspeakers. What makes these special is that the typical non-wanted woofer cone movements (in and out-swing ) on bass impulses, are monitored by a small element and feed back into its internal amps. The result is a very clean and low base performance.

Is there some HAM related stuff involved here??

Yes some, because for receiving FM stereo in good quality you need an outdoors antenna nowadays.
For our 2007 holiday we built a 5el yagi (K6STI design:http://www.ham-radio.com/k6sti/small.htm).
It is now on my roof and serves me well for receiving distant FM radio stations in the range from NNE to South. Its clean pattern and a stone roof on its back does help as it ignores all the local commercial stuff and brings out stations from 150km distance and beyond.
While enjoying the flexibility of a good directional antenna it does have its disadvantages too.
Switching direction to the other favourite station, needs digging out that old rotor control unit and takes ages of time. Now I also have several tuners, which I want to feed as well.

An old VHF vertical was found on a flea market. Its a typical fibreglass version of 1mtr length. Inside I found a small burned ceramic cap. That's also 'typical', as some operators never read the specs.
I tuned this one into a FM radio GP with only 1 radial, made from some brass length.
In my collection of more flea-market stuff I found a small aluminium side mount. Neat !
Last weekend offered lovely sunny weather. I mounted the new omni-vertical to the existing FM antenna setup. Two different coaxes enter my house just at the point where both tuners are located in my shack.

This K6STI type FM radio antenna was made from alum and 40mm PVC pipe. A true home made 1:1 balun is installed to keep the pattern clean. This antenna is easy to build and does a wonderful job.
It was used during our 2007 holiday activities in HB0 .

The new vertical is just parallel to the mast, on the right side.

The vertical was painted black with some 'green spots'.
The radial and mounting bracket were painted too, all just to lower the visual impact.

Does it work?
Yes, the vertical offers my favourite local stations (e.g. Classic Arrow Rock radio) in a range of max 50km. It does not offer the 'FM-DX' like the yagi does. Very, very few stations can be heard and those have S1 and R2-3 only...
But on domestic reception of FM stereo radio stations it performs as expected.

You can never have too many antennas.

.

Receiving Phasing System / Noise Cancelling Controller

2008-04-07T19:22:00.010+02:00

DX-Engineering NCC-1

Finally the phasing control box has arrived !
Very surprised to see this unit is 4 times larger than I expected; it measures 24x24x11.5 cm ( or something like a foot x foot x a quarter of a foot, for that matter).
This is the size of a medium HF rig.

Specifications:

300 kHz to 30 MHz (Switchable in two ranges; <5-10mhz>5-10 MHz)
3rd order output intercept: 32dBm each input, +38dBm both outputs combined
Available phase rotation >360 degrees (between 500kHz and 15MHz)

Go check their website for the rest

Features:

Or better said, in what respect does this unit differ from its MFJ 1025/1026 counterpart?

Phase adjustable through more than 360 degrees (MFJ does much less)
Exceptional dynamic range (30dB more)
Low noise floor (that is usuallly not much of a problem on the Low-bands)
Provisions for optional high pass and band pass filters (see pics)
DC controls with smooth action. Expandable for remote or external control
Provides power and transmit muting for external active antennas

In a nutshell; after some years this is the natural follow-up of the MFJ.
The MFJ is definitely not bad, but it has some drawbacks in practise. Adjusting both input gain setings and finding the right phase are a bit tricky.
The new NCC-1 has no seperate input gain seetings per channel, but a 'balance pot' instead.
Next it has a switch for swapping the antenna inputs (changing receiving direction on the spot !).

Looking at its internals, especially the transformers, this smells like W8JI design:

Looks like 2N5109's under those heatsinks.

Extra options:

Provisions for the high pass and/or band filters
Accessory entry slot for future remote control etc.

So?

You can use it for (local) noise cancelling or, produce a steerable 2 element phased vertical RX array.
And there are some more applications.

What will I do with this unit?

First test this unit at a friends location to get a feel how it compares to its MFJ 'predecessor'.

Next I will start building a second 160m reference vertical in my front yard.
This will be >0.10 wavelength away from the backyard version which allows for a very good steerable phased vertical system (sort of very poor mens 4-square). PA3FGA has proven again and again that his double 160m reference phased vertical system works very well, expecially during contesting.

K9AY in my backyard

2008-03-30T12:56:00.009+02:00

Picture: K9AY in a field day setup during CQWW-CW-2003

The K9AY has clearly proved to be an ideal backyard lowband receive antenna.
With its small footprint of just 9mtr (30ft) and a height of only 7.5mtr (25ft), it will fit about anywhere. Although this is a directional antenna, its horizontal opening angle in the forward direction is e-x-t-r-e-m-e-l-y wide.
Its merit lies in how well it will attenuate local and medium distance signals from the backside.

Exactly what is the K9AY capable of ?
When switching to one of its four directions, you are focussing on finding the best s/n of the DX by choosing which other direction needs to be attenuated.
So in short; you steer the backside pattern to cancel out the interference.

The K9AY has been in many of our contest and/or fieldday setups. Compared to phased verticals and beverages the K9AY has one big advantage; its high angle front-lobe brings you 'little pistols' in the short to medium distance.

Building the K9AY double loop RX antenna
See ON4UN's Lowband Dx'ing about how to build this simple antenna.
Or visit Gary's website at : http://www.aytechnologies.com/
So far I have build several versions of the K9AY steering box, using different (scrap)parts, transformers etc.
There is nothing critical in the design.
However make sure your vertical TX antenna is at a distance of about 0.3 wavelength.
If not, the pattern might be such distorted that you end up with no F/B.

Grounding
A single ground rod about 1m (3ft) into the ground is ok.

We have successfully used a K9AY setup on a mountaintop 2013mtrs asl (6000ft) during our HB0-dxpeditions. As grounding was not possible at this rocky area, we simply used 4 radials under each horzontal loop. That antenna worked extremely well; even the smallest stations within the European area from 160mtrs up to 20mtrs could be heard on the K9AY. Other local antenna's were dipoles, verticals and two Spiderbeams.

Optimal termination
This can be useful if you have the time to adjust to the optimal F/B on a single situation. But at contesting this is not practical. The standard value per band delivers enough F/B already.

For a fixed direction single loop K9AY setup, I reworked the 4 position steering box to choose from 4 different resistance values. Each are optimized for 160/80/40mtrs and it works very well.

The K9AY in my backyard
Having 2 crossed loops in your backyard, taking up all available space is not feasible. Tripping over the horizontal loop wires is another turn-off, especially when fetching a cold beer from the barn during the dark hours !

During my last Christmas holidays I re-measured the backyard and finally found a single hot spot where I could install the K9AY. I just had to try it; it did only just fit.

The 10m length/50mm dia/5mm wall thickness DJ6NI type fibreglass pole was placed in a large bucket, filled with cement sand. I used the ground connection of my "160m Reference Vertical"which I had temporally removed. The same coax and according heavy common-mode filtering was used.

That is me on the picture. It was pretty cold as you can see some thin snow.

How did the K9AY perform in my backyard?
Directivity was all there; I could easily eliminate some known 160mtr european beacons switching front/back.
But the total "F/B behavior" was not as good as I was used to. Perhaps being so close to the house the pattern wasn't optimal. But then again, almost any antenna out in the field works better.

My biggest concern was the large amount of close-in signals at night. All europeans were MUCH louder compared to the 160m Reference Vertical I was using for so many months now.
Since the vertical has a low-angle "doughnut" radiation pattern, its high angle signals are all attenuated. The K9AY however, does have high angle reception at max gain.
I could hear DX, but the band was constantly filled with strong EU signals :(
I should have realized that up-front.

After 3 days of trying and some further experimenting on fine-tuning the termination etc. I removed the K9AY from my backyard. It did not deliver the improvement I needed.

It is good to have a reference antenna.