After several weeks of trying I finally got lucky and had two QSOs via EME. Below are several screen shots from the contacts. The only thing that was different this time was the antenna. I used my 8 element DK7ZB instead of the thirty year old 9 element Tonna. The Tonna is showing signs of it's age and I'm wondering if the corrosion is affecting it's gain.
Equipment
Modified Kenwood TM255E (SI570 LO, IF tap)
Homebrew SDR tuned to TM255E IF
Homebrew 300 Watt amp (Freescale MRFE6VP6300 mosfet)
8 element DK7ZB (gain 12 dBd) Software; WSJT-X v1.7.0-rc2 PowerSDR-IQ
So I'm pretty happy with that and looking forward to more contacts.
Transmitting RO
Completed QSO
The second contact was an answer to my CQ, pretty suprised I can say
It's the ultimate challenge of amateur radio, Earth-Moon-Earth also known as moon bounce but is it possible with a small station like mine? Until recently I would have said no but after using MAP65 from K1JT I'm starting to think that maybe it is possible.
I've been using SDRs for some time now on VHF, so I already had available the IQ output needed to use MAP65. This allows the decoding of all JT65B signals within a 90kHz bandwidth. I've used the software to monitor beacons on Two with good success, at times being able to decode four beacons at the same time, GB3WGI, GB3NGI, GB3VHF and F5ZRB. But it never occurred to me to try and hear anything off the Moon. That was until one evening while watching an art programme an item appeared about artist Katie Patterson's Earth- Moon - Earth.
Katie used EME to record Beethoven's Moonlight sonata complete with gaps due to fading and then replayed it on a modern player piano. This romantic idea of radio waves going to the Moon and back was an inspiration so I started reading all about EME. I soon discovered that with JT65B, on Two, small stations were having success with single yagis and no elevation.
Help needed
Ground gain or in this case sea gain
Apparently, EME is possible with 100 Watts and a single Yagi using JT65B. It is often achieved at Moonrise or as the Moon is setting when ground gain is available. I took this photo of the Moon over the sea a while ago and if I've got this right it should help to illustrate the principle. Light from the Moon is taking two paths to the viewer, direct and that reflected from the surface of the sea. The reflected light adds to the overall illumination. In radio that can add as much as 6db to the signal at 144 MHz. There's much more about ground gain online as a search will reveal but it's just like having four Yagis, not just one. Of course, it's only available when to Moon is at low angles as in the photo. ↗
First monitoring
So with this in mind, I started to monitor off the Moon. Pointing my small 9 element beam towards Moonrise I left MAP65 running overnight. Moonrise would occur in the early hours so I wouldn't know if anything had been received until the following morning. Come morning there was just one line in the band map, "73", time, signal strength, etc. So to see if anything else had been received I opened up the text file Map65-rx found inside the MAP65 folder. It contained all decoded data received through the night and to my amazement several stations had been received, two Russians and an Italian. Pretty encouraging but I had in the past, while monitoring beacons, seen false decodes so to be sure I turned off the Deep Search and renamed the CALL_3 file to be sure that I was indeed hearing off the Moon.
Once again I pointed the beam towards Moonrise, left MAP65 running and waited to see what might be decoded with the Deep Search disabled. Once again there were several stations decoded and this time they could not be false decodes.
More monitoring
Over the following weeks, I continued to monitor and I soon started to realize that signals could be heard from Moon elevations of just 1 degree to as high as 25. Outside this range decodes are few and far between but they did occur even 1 degree below the horizon on one occasion and at 60 degrees above.
Next.......
I've improved receive performance by building a new preamp. I'm looking very carefully at the transmitted signal as getting audio harmonics to a low level seems important to me. I need to familiarize myself with the operation of WSJT JT65B. Just monitoring is easy but TXing is going to be more demanding. I need to test my amp at the high duty cycle of JT65B........etc...etc....... but hopefully I'll soon be ready for that first contact. I'll post here if I make it.
Cheers & beers
Dave G8TTI
UPDATE
15/12/2016
Well, I keep trying but not had much luck so far. Was spotted on Livecq by a Dutch station but can't help wonder if that was tropo. Also had a QRZ, well I think it was for me. I'll just have to keep trying. Amp works fine and I have a 12dBd antenna to try, hopefully, that will help.
73
Had some success with 23cms WSPR but found that transmit with my old transverter will not work as there is far to much drift even tough I've ovenized the LO. Needs more work on the oven.
At the beginning of June 2016 the WSPR VHF spot frequencies in IARU Region 1 where removed from the band plans.
At the time I wrote this response but have only now decided to publish it.
I'm
new to VHF WSPR and am really enjoying it. I've been on Two for over
30 years and if you'd ask me before I started using WSPR if I could
put a signal into JO23 (600Km) with 5 Watts under flat band
conditions I would have said noway but with WSPR I can! I'm impressed
and would like to find out what more can be done. So I'm not going
away yet but I do believe we should take the olive branch offered by
the RSGB VHF Manager and on Two, which is where the problem seems to
be, all just QSY to DIAL 144.490500MHz.
We
should also ask the VHF Managers to re-read their handbook paying
particular attention to these passages;
“The
basic philosophy behind bandplanning should be:
• to
assign frequencies for certain activities in such a way that all
current users can practice
the
various modes of amateur radio with a minimum of mutual interference,
provided they
are
using state-of-the-art equipment and communication techniques”.
“Technical
investigations by amateurs, be it in the classical field of
propagation research or on
modern
digital communication techniques etc. are a laudable and legitimate
aspect of amateur activity”.
“The
definition of the Amateur Service implies that bandplanning should
take into account all
aspects
of amateur radio – self-training, intercommunication and technical
investigations.
Consequently,
for any band the bandplan should aim to accommodate for the maximum
number
of amateur activities (modes, techniques), both now and in the
future.
Clearly
there are impossible situations: CCIR ATV cannot be carried out in
the 144 MHz
Here's my WSPR setup.
Two Metres: home brewed hybrid SDR (has IF at 10.7MHz) nine element Tonna.
Four Metres; home brewed SDR loosely based on a design by WB6DHW and a two element HB9CV
Have the same arrangement on Six but not used it to date.
Can also receive using home brewed TRX with SDR IQ output from 160 to 2.
Antennas are 80 metres from the house with amplifiers and pre-amps in shed below the mast.
Keeping power low has been no small challenge!
I have recently return from a holiday to the South coast of England. I felt it would be great fun to operate WSPR from the holiday cottage that overlooks Start Bay. It is a wonderful location. With fantastic sea views. So I was keen to see what spots I could get.
I took along my old IC 706 but did not have an antenna suitable for HF. I did however have a mobile whip that I could press into service. At least put it on to the car and see how well that would work. I didn't know where it would be possible to install an antenna otherwise. Looking around the cottage I realized that it would be possible to suspend the mobile whip from the guttering.
The antenna hanging from the gutter
So I set about doing this, as you can see from the picture. It was quite close to the cottage and had no ground plane. So I was not sure how well it would work or how or where it would match. But I discovered that it matched quite well around about 10 MHz. So the choice was obvious, I would use the antenna on 30 Metres. I had already reduced the output power from the 706 to just one Watt. So with one Watt, a tablet and a makeshift antenna I gave 30 Metres a try. To my amazement the first spot came from Australia, the next from North America. Quite something for one watt and a lashed up antenna. I continued to WSPR on 30 Metres for the following two days, but then decided to try 20 Metres and retuned the antenna slightly. I found the results were not as good. Seems as if 30 Metres is a good band, one I have not tried before.
Although it was interesting to see where I could reach on HF I decided that Two Metres would be worth a try as well. But as I did not have an antenna with me for Two I had to set about making a dipole which I did using a plastic coat hanger and some stainless steel rod. Listening around it seem to recieve signals fairly well from the high vantage point overlooking the sea. So I decided to post on the WSPR Facebook page that I was operating from an alternative address on the South coast of the UK.
I don't know how legal it is to operate / A when you cannot identify yourself to 6 digit QRA locator, as licensing conditions require, so I went to the trouble of putting on the WSPR website that I was actually operating /A thereby letting anybody caring to take the trouble to look up my call that I was operating away from home. I'm not sure, as I said, whether this is legal, but I did it anyway. I think there must be many people who perhaps stretch the licensing conditions a little bit using WSPR, but I don't think that these infringements are anything other than slight twisting of the rules. For example, leaving your station running while you go up top of the garden or are in bed sleeping. I wonder whether strictly speaking this is within licensing conditions. Let's hope OFCOM are happy.
Unfortunately, the results on 2 Metres were disappointing with no spots whatsoever even though a station in north France was beaming my direction. I transmitted for several days but he heard nothing of me. Power output on 2 Metres was just 10 Watts, antenna was a dipole.
I'm continuing to WSPR
on 144MHz with some success I think. At this time there is plenty of
activity from Holland, so I'm getting spots, unfortunately not
often able to spot the PA stations. Although there are quite a few
traces on the WSPR waterfall they do not always decode.
Here is an example that shows a relatively strong station with
Doppler shift that would not decode. This seems to be a problem with
WSPR on Two Metres. It would be nice to try WSJT-X on tropo as
I understand that Doppler would be less of a problem.
Strong but Doppler shifted signal probably from Holland
Below is another that failed to decode.
NO decode WSPR 144MHz
So I am sorry if you've spotted me and I have not spotted you but this probably is a two way problem, there is just more activity in Holland, so thank you for that!
WSPR on 144MHz has been
something that I've played with over the past few days.
Running twenty Watts and a 9 element beam produced the results in the
image below. Although I can't say these distances are DX they
pretty good considering the flat tropospheric conditions at the time and the low power.
If I think back to when I first became interested in radio, a thirteen year old trying to pick up the off shore pop pirates of the sixties, a short run of wire poked into a small tranny radio crackling and popping was about all you could expect. That was over 48 years ago but I remember those days very clearly.
There was something magical about it, despite the crackling signals, the static, the night time interference. The radio provided the pop music we were after, the weak signals just adding to the romance of it all.
I lived over a hundred miles from the nearest 10kW pop pirate, a cheap transistor radio struggled.
Well it was all a long time ago, things have moved on somewhat. The pirates went a long time ago. Medium wave seems so old hat I can't believe anyone listens there today. FM, DAB, crystal clear reception are the norm and expected. Internet radio, never a crackle or a pop heard! and thousands of stations to choose from all with no static, no idea of the medium involved just lovely clear interference free music, or whatever you want.
So what's this got to do with amateur radio? Not very much but I'm left wondering how we can ever hope people, young people in particular will ever discover the thrill and excitement of radio. They will never have the need to poke a wire into the tranny radio, never hear how the signal changes as night falls, never wonder how they could improve reception, longer aerial, different radio...... Never, in doing, happen across amateur radio. There's the problem how do people discover this hobby? I know, I know, CB has brought many to amateur radio but do young people use or even know what CB is ? Why would you when you've a mobile phone in your pocket?
This is a big problem for the hobby, let's hope that something new comes along so people will discover amateur radio in the same way that the pop pirates of the sixties and CB of the early eighties were a boost to the hobby in the UK. It's really hard to think what it might be. Any ideas?
