50 MHz Bandpass Filter from Cross Country Wireless (UK)

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!

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

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

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:

1. Remove coax cable from CN1 and insert at CN7
2. Remove pin-diode D30
3. Remove pin-diode D43
4. Bypass R35 (5k6 at CN7 test point input)
5. 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 III; Building antenna's just for the fun of it

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.

Es II

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 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..........

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

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..........

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.

Peurto Rico on 6m with 15W output only !

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......

17 Beautiful Summer Holidays in HB0

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

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