Radio - HF to Microwaves

Well, youv'e gotta do a test or two, youv'e.................

The XORgan went for a short recital on HF today running 1 Watt first 0n 40m then 30m.

Right Click on the pic. and select View Image for full size.

People on WSPR thank the RX stations on the Chat page, OK, well, thanks to following stations but then you had no choice did you.

2009-10-31 12:40 G3ZJO 10.140191 -17 0 IO92ng 0.05 DL0NOT JO40jf 709 105
2009-10-31 12:40 G3ZJO 10.140181 -18 0 IO92ng 0.05 OH2MZA KP01ro 1692 44
2009-10-31 12:40 G3ZJO 10.140185 -18 0 IO92ng 0.05 DF2LV JO44rs 737 64
2009-10-31 12:40 G3ZJO 10.140186 -1 0 IO92ng 0.05 DL2NI JN48ul 860 115
2009-10-31 12:40 G3ZJO 10.140193 -10 0 IO92ng 0.05 OESWL JN67qu 1127 110
2009-10-31 12:40 G3ZJO 10.140207 -6 0 IO92ng 0.05 DL4SR JN49wc 834 111
2009-10-31 12:40 G3ZJO 10.140185 -23 0 IO92ng 0.05 W3CSW FM19kd 5811 288
2009-10-31 12:30 G3ZJO 10.140189 -22 0 IO92ng 0.05 W2WH FN30kr 5437 287
2009-10-31 12:30 G3ZJO 10.140183 -15 0 IO92ng 0.05 DF2LV JO44rs 737 64
2009-10-31 12:30 G3ZJO 10.140221 -4 0 IO92ng 0.05 PA0BWL JO21ss 442 95
2009-10-31 12:30 G3ZJO 10.140186 -4 0 IO92ng 0.05 DL2NI JN48ul 860 115
2009-10-31 12:30 G3ZJO 10.140207 +4 0 IO92ng 0.05 DL4SR JN49wc 834 111
2009-10-31 12:20 G3ZJO 10.140207 +4 0 IO92ng 0.05 DL4SR JN49wc 834 111
2009-10-31 12:20 G3ZJO 10.140186 -19 0 IO92ng 0.05 K1JT FN20qi 5561 287
2009-10-31 12:20 G3ZJO 10.140186 -4 0 IO92ng 0.05 DL2NI JN48ul 860 115
2009-10-31 12:00 G3ZJO 7.040097 -11 0 IO92ng 0.05 G6PHT IO92of 7 129
2009-10-31 12:00 G3ZJO 7.040079 +3 0 IO92ng 0.05 GM3RXU IO86qg 459 346
2009-10-31 12:00 G3ZJO 7.040125 -8 0 IO92ng 0.05 ON7KO JO21ce 370 107
2009-10-31 12:00 G3ZJO 7.040096 -21 0 IO92ng 0.05 LA9JO JP99gb 2124 21
2009-10-31 11:50 G3ZJO 7.040079 -1 0 IO92ng 0.05 GM3RXU IO86qg 459 346
2009-10-31 11:50 G3ZJO 7.040126 -4 0 IO92ng 0.05 ON7KO JO21ce 370 107
2009-10-31 11:50 G3ZJO 7.040096 -16 0 IO92ng 0.05 LA9JO JP99gb 2124 21
2009-10-31 11:40 G3ZJO 7.040095 -17 0 IO92ng 0.05 EI9FV IO63vk 381 292
2009-10-31 11:40 G3ZJO 7.040096 -14 0 IO92ng 0.05 LA9JO JP99gb 2124 21
2009-10-31 11:40 G3ZJO 7.040098 -9 0 IO92ng 0.05 G6PHT IO92of 7 129
2009-10-31 11:40 G3ZJO 7.040148 -26 0 IO92ng 0.05 G6PHT IO92of 7 129
2009-10-31 11:40 G3ZJO 7.040080 +3 0 IO92ng 0.05 GM3RXU IO86qg 459 346

Tests on 2 bands over and done in 1 Hour, glad I didn't stay on longer, its was pain re tabulating that lot.

The ability to ‘go anywhere’ with an MEPT is increasingly more desirable, unless you want to sit ‘Rock Bound’ on 30m or use DDS.

Many of us have a Multiband TX/RX which can run QRP but for some modes, (WSPR), a computer is needed in TX only mode which makes a mockery of the term QRP as applied to Station power consumption.

We have produced PIC based MEPT’s for Multi Modes and WSPR.

Some have recorded WSPR audio on MP3 and re played that for Computer-less operation.

I think Computerless is a well understood term in all walks of life. Well this uses a lot less Computer than most. This uses a small PIC processor with no external memory, sound card, hard drive, video card, monitor, keyboard or mouse and I swear it has never had relations with Microsoft, or Monica Lewinsky.
For the purists I shall say PC Less in future, if I remember.

I have now produced the KISS WSPR Organ. Sorry Whisper refusenik’s for the name, it does QRSS just fine.

The name stems from my original idea of using a musical tone generator to produce the WSPR tone frequencies. Talking to an Organ engineer yesterday morning soon proved that approach to be far too complex and my simpler KISS idea was implemented.

The Output can be applied to any HF/VHF SSB Transceiver or better, a simple home brew SSB TX.
The PIC will provide QRSS Morse, Hell, Patterns, WSPR whatever, plus PTT TX/RX switching for any pre determined periods
There is an advantage over the ‘generate on frequency’ MEPT in that nothing is running on signal frequency so the generator can be left running during receive periods.

Two Xtals on the ‘same’ frequency use a single 74HC86 for Oscillator, Mixer and Buffer. One Xtal is pulled 1.5KHz HF and the PIC modulates this Oscillator also.The modulated 1.5KHz signal from the Mixer is selected, fed to the Buffer and feeds the TX Data Audio Input via a Set Level pot.

Just one chip and that’s it. And it works, this from G6AVK at 127Km on 50MHz.

And on WSPR it is performing well no drifts in some 10Hours use, again thanks to G6AVK for the reports. The severe Aircraft Scatter has caused a bad decode but we are used to that on the direct path.

Sorry the power level shown is erroneous due to the experimental nature of the project, on 6m this is less important than on HF for any database information. The level stated when accurate is actual Power into 50 Ohms at the Antenna Socket not ERP. The use of beam antennas make any ERP estimate impossible (was the RX station on the side or back of the beam).

The input will be from your favourite PIC modulator with suitable level adjustment and shaping. The LED I show used as a Varicap can be either way up depending upon your normal methods. I use it reverse biassed, the opposite of how its drawn:-)

I added an RC Audio LPF to the output and a divider and pot for easy deviation level setting.

I use my blog as a reference for myself. Today I looked for a picture and description of my 6m si570 (DDS) MEPT test set up here and found I mentioned it but posted nothing.

I thought I had better put the DDS in brackets they are generally getting called DDS now which isn't strictly correct.

So here we go.

Here we see the s1570, SL612 Mixer, 16F628PIC Modulator, 2n3866 equiv PA.

In total 8 active devices 5 IC's and 3 Transistors for 100mWatts of WSPR on 50MHz

I think I can say I have the drop of Aircraft Scatter now. I noted straight WSPR reflections which de-coded from the North, with the aid of G6AVK I was able to predict the flight path of the reflecting Planes.
Next G6AVK and I beamed SE to the Thames Approach and achieved some straight de-code-able reflections of WSPR.

In the next step I calculated possible Airline routes that could produce straight reflections for our two stations, G6AVK and G3ZJO, the calculations are only valid for these or similarly located stations. A test this week of one route produced some near reflections but nothing that de-coded.

Today I asked G6AVK to beam to Fishguard as per my map.

Within 45 minutes we struck lucky with a plane on the right track and the following de-code.

Only the reflected signal de-coded, the direct path being corrupted by local A/S. The Doppler shift shows only 24Hz which equates to an Aircraft Speed of only 257.68KmH Yet something else to think about.

The Spectran Grab shows some tangential variation which could well corrupt the calculations.

Wednesday the 21st of October saw the Peak of the Orionids Meteor Shower coinciding with a 6m activity day on WSPR.

I could have been on JT6M looking for M/S activity or joining in the E/S opening to Spain, however I decided to beam East with WSPR. G3XBM near Cambridge was on, after some overhead A/S was observed I captured an interesting one.

Now all we need to do is explain the signal which defies all the rules for Aircraft Scatter. What I think we are seeing is a meteor shower relatively overhead of G3XBM this has caused E layer reflections for some 15 seconds followed by some fast moving trails for another 15 secs. at the end of the period some fast moving patches of ionisation (from break up of a Meteor?) cause reflections that I think resemble smoke rings.

If you have lots of knowledge of extended period reflections from meteors it would be great to hear your interpretation.

The Sporadic E from the meteor shower lasted for some time, this later Grab is easier to explain.

I turned my beam to the North East, knowing that SM6NZV and OZ1PIF were operational.

2009-10-21 07:58 SM6NZV 50.294406 -26 0 JO57xk 5 OZ1PIF JO65an 209 179

The trace is at the correct frequency for SM6NZV and the WSPR signal is visible for the complete 2 Minute period via Sporadic E from the Meteors, at least 5 meteor pings are clearly visible and were audible. Unfortunately the signal did not de-code.

Some of the activity here at the weekend was devoted to attempting to get some signal by any means to SWLGM Mark in Edinburgh. Very little signal was seen from either G6AVK or G3ZJO on Marks 6m Zepp antenna.

The use of WSPR gave the chance to look for Aircraft Reflections which produce a double de-coded report. There were several examples spotted and screen grabs taken of them. I am still not certain of the distance involved to the reflecting plane. Currently I think it is quite large c.500kM.

A most interesting de-code came late in the day. A double de-code of my signal at G6AVK.

This shows only 1dB less signal strength for the reflection compared to the 'direct' path and a 51Hz shift.
Luckily G6AVK also captured the WSPR Waterfall and better still a Spectrum display.

The top trace is the Direct Path signal, 51Hz below is the Reflection which de-coded, clearly many dB lower than the Direct.
Between these two is a curving reflection, stronger than the direct signal, this type of signal has never been seen here to decode the WSPR data.
After some thought I can offer an explanation of the mechanism involved. I am quite happy to listen to alternatives.

The trace 51Hz below the top direct path one produced the de-code, it come from an Aircraft flying North in the North UK Air Lane.
The curving trace comes from a much closer (to G6AVK) Aircraft, joining the South South East Air Lane (off to the South of France) and reaching a cruising speed very close to that of the Aircraft travelling North. Using standard speeds in a control area is the way that Aircraft are kept apart. Reaching the right place at the right time is a game of chance, we had been playing roulette all day.
So is the alignment of G3ZJO G6AVK and The SSE Air Corridor a possibility, yes this is only a rough layout on the map.

Right click and select View Image for full size.

So finally why the odd report of signal level from WSPR. I believe that the signal from the closer Aircraft to the south swamped or reinforced the complete reflection, the de-coder giving an average strength reading over the whole period. Joe?

Clearly there has been a spell of QRM on 5MHz which has conspired to mislead me. Much of the Interference was seen in the Shetlands as well as at my station.

The above 'curtains' were short lived. The 100Hz spaced carriers persevered for a few days.

This managed to convince me for a time that the 25Hz bands were harmonics of the 100Hz ones, when the QRM varied the 100Hz carrier were contiguous. Yes sure they are all sync'd to the 50Hz Mains supply so they would be.

Today the 100Hz carriers had gone, both here and in the Shetlands, at 07.09 UTC the 25Hz carriers started. I decide to take a rest from house maintenance and do some Direction Finding.

At 08.16 UTC I asked a neighbour "would you switch your TV off please".

It was a December last year purchase, hence the QRM I had seen on 80m, a Panasonic Plasma TV model TH-42 PX80B. Fairly new neighbours who I have not had the chance to chat to and say if you buy a new TV don't ever buy Plasma will you. I just hope the product life is very very short.
Just like the Home Plug PLC fiasco modern products do not meet the standards needed to prevent interference on the Short Wave bands. Ofcom the people who should enforce the standards are a feeble pawn of the Government and money talks.

Recent WSPR activity on 5MHz has seen power levels reduced to 0dB, 1mW and consistent decodes at distances in excess of 1000Km.

I was pleased to achieve 890Km with 1mW myself, but even more pleased to receive other stations who are running that power level. At this QTH I have high noise levels and a regular almost constant comb of 4 or 5 carriers spaced at 25Hz.

I don't think it is local, i.e. TV's or computers, it seems to come and go with propagation. It threw me the other night when just after 23.00 it went off abruptly. Maybe a TV then. However note the 10 minute break in the screen grab above, then change of format, not consistent with TV or computer use.

This is what the carriers look like on Spectran.

DL6NL suggested comparing the double width signal with the correct one to see if it is indeed OK2SAM who is transmitting it. Problem where to you find the correct one. Well I decided to generate it locally using very low power on 30m into a Dummy Load. This I thought will vindicate the suspect as I am not sure how Patrick F6IRF knows it is him.

The capture below shows my signal at the bottom, the strongest trace, and the locally generated one above with details as reported as Spots.

Comparison is not that easy due to size difference but conclusive, OK2SAM is transmitting a double width signal. It will be interesting to find out if it is indeed a home brew WSPR set up he is running. The Locator is a Portable location, and he does not seem to receive any stations.

Finally to aid identification I have separated individual lines of data for comparison, the middle lines suffer from noise, the best one to illustrate is the bottom line. Sized to roughly the same dimensions.

I am now in communication with Michael OK2SAM, he is running a most interesting home built 3 band WSPR beacon, I am sure he will find out the cause of the problem soon now he knows about it.

On the 12th of May 2009 I spotted a strange wide signal on WSPR.

At first DL6NL and I thought it could be a new home brew WSPR TX not yet adjusted correctly. I checked the exact width of the signal and found it to be exactly double the correct deviation. Unlikely I think that someone capable of producing his own system would adjust to precisely double.

One way to achieve this would be to use a system which used a doubler on the correct WSPR signal to reach the desired transmit frequency.
F6IRF has recently seen the signal again, it seems to be the same signature, the mystery deepens, does this operator know what he is doing, surely he has never had a decode.

So far observation at G3ZJO of straight line reflections from Aircraft have concentrated on the departing path as planes travel North up the UK and turn toward the USA. This has produced the now classical approx 60Hz negative Doppler shift.

Today an accidental alignment of beams at G6AVK and G3ZJO has produced AS which approaches the path between the two stations then vanishes. I surmise that these are reflections from Aircraft on the Thames Estuary approach from Europe which may well vanish when past the front of the AVK beam.

Looking at the capture at 13.30 GMT there is a straight line AS reflection which decoded, it has a 53Hz shift but this time positive Doppler. This is the first time positive straight line Doppler shift has been observed here. Again I assume from an Aircraft on the EU Thames approach heading toward G6AVK and G3ZJO at 53x540/50.294436 = 569KmH

The Modular DDS MEPT was completed ahead of the start of the Sporadic E season, I have put it on On Air Test on 28MHZ (10m). Reports on the WSPR ident have come from Portugal, Italy, Norway, Slovenia, Iceland, Germany, Spain and Greece. A very pleasing start.

Always extra pleasing is a capture or three of the Visual modes.

First in was Paolo IZ1KXQ in Italy.

Next up a capture of the WSPR display but from France F6GUU a Country we don't see many reports from.

Edit : And another from Pat F6IRF in JN35AU on the 7th of June.

Third Spain from David EA1FAQ.

The MEPT is running 300mW, the Antenna is a 6m CB type Vertical at ground level. I knew 10m was going to be good fun. this is the first time I have run a QRP MEPT on the band.

A great quote from an Alaska station today, "its so exciting I may not be able to hold my water". I know just how he feels.

Today was superb for visuals of the Airliners in the UK South / North Air Corridor. The clear blue sky made it easy to observe Aircraft travelling North 'over my back garden' and South 'over the front'.

Here is just one Plane of the constant stream which passed my QTH and my 6m Vertical Dipole today.

Right Click and select View Image for full view.

It would be interesting to find the true distance at which this one passed, I estimate 1 Mile. I think Aircraft in the Corridor can be anything from Overhead to 20 Miles away.

My last blog entry covered an experiment to prove that it is possible to get a straight line reflection from an Aircraft travelling away from both the originating, TX, station and the receiving station.

The Aircraft needs to be, I believe on the same bearing as that of the path between the two stations.

At my QTH this is merely a waiting game, there are so many aircraft on the S/N corridor that finally one will fit the equation.

Previous tests with G6AVK did not achieve the desired result. I think that, while his omni directional signal reached me fine, by the time it got to Aircraft sufficiently North of me it had run out of 'steam'.
The addition at G6AVK of a mast and rotatable 6m Beam means that strong Aircraft reflections from the North are now possible.

I pointed my beam in line with the S/N UK Air Corridor G6AVK beamed toward me.
Note the trace at 19.32. There is the direct signal from AVK. A long descending trace from an Aircraft, which has passed me and is heading North, on a track at a tangent to the path between AVK and ZJO. Third a parallel trace, ‘classic’ 61Hz shift equating to an air speed of c.600Km Hour.

This produced 2 decodes of WSPR on the two frequencies.

2009-05-29 19:32 G6AVK 50.294482 -18 1 JO01ho 5 G3ZJO IO92ng 127 306
2009-05-29 19:32 G6AVK 50.294421 -25 0 JO01ho 5 G3ZJO IO92ng 127 306

I think we can now say that this is the definitive explanation of the phenomena. Repeatable by experiment, using 3 different signal sources.