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.
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.
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: 5elWhat 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.
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 :)
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.
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.....
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 !
Did someone mention 'Beverage Antenna' ???
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 :)
