Happy New Year

I prefer looking forward to looking back over the year so I'm not going to indulge in a long navel-gazing retrospective of 2012. Nor will I be making any new year's resolutions for 2013 as if I did I expect most of them would be broken for perfectly good reasons whilst other things will be achieved that I haven't even thought of yet.

The only thing important enough for me to make a resolution about is to keep on getting healthier and beating that brain tumour into submission! If I could get my driving licence back and regain access to the Great Outdoors that would make me happier than I could possibly say.

I wish all my readers good health and happiness above all else in 2013. See you next year!

Airborne!

I told Tim, G4VXE, about the trouble I was having getting a USB TV dongle to work as a VHF/UHF SDR and he emailed me a couple of files. One of those was an installation script which I suspect is the same one mentioned in the article "Cheap and Easy SDR" in the January 2013 QST which a couple of people mentioned. I had read this article at least twice and then forgotten all about it, which is a shame as it would probably have saved me several hours of abortive messing about.

I ran the script once and it seemed to work but I still could not get anything out of my ezcap dongle. I then used MagiCure to turn back the clock a few days to before I started messing about, and then ran the script again. This time it worked. I ran SDR# and it appeared to be working. I set the frequency to somewhere in the FM broadcast band and within a couple of minutes I was listening to Classic FM on 99.9MHz in stereo.

SDR# receiving BBC Radio 3 in the FM broadcast band

This was all very good, but I have any number of radios able to receive FM radio. I wanted to try receiving ADS-B aircraft beacons. But although both ADSB# and RTL1090 (ADS-B decoders) seemed to work (i.e. didn't display any error messages) they were not decoding any data. I used SDR# to monitor 1090MHz, the ADS-B frequency, and I could not see or hear any signals, though I have no idea what they are supposed to sound like.

I decided to reinstall the second dongle which had worked as a TV receiver. Then, on a whim, I thought I would try running SDR# to see if it would connect with the other dongle. To my great surprise, it did. What's more, it seemed much livelier (more sensitive) than the ezcap dongle. I tried both RTL1090 and ADSB#. Both worked and immediately started decoding packets! I started up ADSBScope and within a few seconds aircraft began to appear on the screen!

ADSBScope plotting aircraft overhead at G4ILO

After a while I got cocky and decided to see if there were any other free aircraft-plotting applications I could try, so I downloaded VirtualRadar. After a bit of trial and error I found the right settings to connect with ADSB# and I was soon seeing the aircraft passing overhead plotted on a Google map.

VirtualRadar plotting aircraft overgead at G4ILO

Strangely enough, both RTL1090 and ADSB# think they are talking to the ezcap dongle! Not surprising I suppose as I have not installed any other drivers. It would be nice to be able to use the equipment as a TV receiver as well but I suspect that would break everything! I should probably quit while I am still ahead.

Both ADSBScope and VirtualRadar are nice applications, and I couldn't say one is better than the other. VirtualRadar runs as a web server and you have to point a web browser at it to see the display. It shows more information such as the starting and destination locations of many aircraft, which is interesting. But curiously VirtualRadar does not display aircraft callsigns (like G-ADSB) while ADSBScope does.

This is looking to be an academic question as this morning ADSBScope has decided to stop working. It won't talk to either RTL1090 or ADSB# but complains repeatedly about a "comm error." Ah well, at least VirtualRadar and SDR# are still working.

Grounded

I hope all of you had a very good Christmas. I was not very well a couple of days before the holiday. Nothing to do with my cancer, I'm glad to say, but possibly a result of all the treatment for it. I'm feeling a lot better now, but have got to have more tests and may have to go into hospital for removal of gallstones or kidney stones - I'm not sure which as I've been told I have gallstones but I have had some sharp pain in the kidney area. As a consequence of this I haven't felt much like getting up at a reasonable hour to start the beacon monitor or HF APRS gateway.

Creative Design New FM+DAB USB DVB-T RTL2832U+R820T

Before Christmas my interest was piqued by Tim G4VXE's adventures using cheap digital TV dongles as receivers for, amongst other things, aircraft spotting. The first dongle I ordered was described as a Creative Design New FM+DAB USB DVB-T RTL2832U+R820T with antenna, and cost just over six quid!

EZCAP eztv645 RTL2832U / FC0013 USB DVB-T Digital TV Dongle

After a bit more reading up on the subject I began to doubt that this would be compatible with the software everyone was using so I ordered a second one, described as an EZCAP eztv645 RTL2832U / FC0013 USB DVB-T Digital TV Dongle for WIN7 LINUX SDR which was a massive £8.68 including postage from Hong Kong.

Both arrived yesterday. I tried the ezcap first, but my shack PC didn't like the mini-disc that came with it so I was unable to test it as a TV receiver. Following the instructions for the aircraft decoders I installed the driver using zadig_xp, then downloaded and ran rtl1090 which is a decoder for the ADSB packets. This seemed to work - no error messages appeared - but nothing else happened. To display the aircraft data that I hoped to receive I downloaded ADSBScope and installed it. I then spent a lot of time trying various options to connect ADSBScope with rtl1090 but got nowhere. I also tried SDRSharp in the hope that I could use the dongle as a VHF/UHF SDR, and ADSBSharp as an alterntive to rtl1090. But neither of them received anything.

After a while I gave up, disappointed. I then installed the Creative Design dongle and its software. A scan for channels found about 55 TV channels with its quarter wave antenna hung in the window. So it was obviously working. Just not with any of the SDR or ADSB software, as I had suspected.

This morning I tried installing the ezcap software CD that my shack PC couldn't read on another computer. The software installed perfectly on this laptop so I plugged in the dongle and hung the antenna in the window. The software scanned for channels and found precisely nothing. I think this proves conclusively that I have a duff ezcap dongle. Ah, eBay!

Winter blues

I like Christmas, but with that sole exception I hate this time of year. The short days, when it's dark at breakfast time, dark at tea time, and in between the sun struggles to reach an elevation where it can be seen over the tops of neighbouring houses.

It's not just the daylight the sun fails to make much impact on. There's next to no propagation on any of the higher HF bands. I believe that LF band enthusiasts have their best time at this time of year. But I have never been lucky enough to have an antenna for the LF bands. My attic multiband dipole will work on 80 metres but it is shortened so much that the usable bandwidth is barely 60kHz. It is really only usable on the QRP CW frequency and the PSK31 operating frequencies.

Yesterday I thought I would try some digital work on the 30m band. I couldn't hear any PSK31 at first but I did hear some JT65 so I thought I would try that. I made three QSOs including one with N4ABN which I thought was quite good nfor mid-morning. The trouble with JT65 is that I find it difficult to maintain concentration. It's 50 seconds before anything is decoded, and during that time my mind has drifted off and I have missed the moment when I should have responded.

Just as an aside, I noticed a quirk with the JT65-HF software. I don't use CAT control of my K3 (never could get it to work) so I have to set the frequency of the radio and the software manually. But whenever I did this, after a few seconds the frequency would reset itself to 0. I happened to notice that the frequency was being displayed with a comma as the decimal separator. I had left the PC configured like that after testing the fix for the problem with KComm. On a hunch, I reset the separator to a dot (period) and lo and behold the frequency stayed as I set it. I'm surprised that no-one seems to have spotted this but at least we know now how to fix it.

After making a bit of a meal of three JT65 QSOs I decided to switch to PSK31. Although it is not such a good mode for DX, if proof were needed, there were 3 or 4 spots of me on JT65A in the USA but my PSK31 at slightly higher power never penetrated beyond Western Europe.

I do find PSK31 a more rewarding mode to operate, though, because you do usually find out something about the other operator or his station. Having said that, has anyone noticed a trend towards shorter QSOs in PSK31? Quite often now it's name, report, qth, locator and goodbye. Whilst I can't say I miss knowing the make and model of the operator's computer and the colour of the interface cable, I do like to know what power they are running and what antenna they are using.

The accidental QRPer

HF band conditions are not all that good at the moment. I was on 20m (in itself an indication that conditions on the higher bands are poor) and tried to call a couple of US stations but all I got was QRZ? I heard Jarda OK1DMZ calling CQ and he was a strong signal so I replied. Back came a 599 report. It was only when I sent the station details and sent my power that I realized I had it set to 5 watts!

I've lost count of the times I've found myself accidentally operating QRP because the rig was set to 5 watts after having been WSPRing at that power level. In better conditions I've made several contacts before realizing my mistake, which just shows that QRP does not always result in having a weak signal. But when conditions are like they are at the moment, power helps!