Radio and rails...

After a long delay (other work, life getting in the way, general laziness etc) I ran some more tests on the Pibox. With the fans disconnected (actually, one disconnected itself!) and the case assembled I've been running the box to see how bad the temperatures get. With two of the three Pi cards operating, and all 3 powered up, pi-star, which is on top due to the DVMEGA hat settles at 60 degrees C, and the utility Pi which has a Discone attached settles at 50. So not actually bad. I think what I will do is go back to Plan C or whatever it was and run the fans via a transistor hanging off the GPIO port of one of the cards so the fan comes on if it is getting a bit steamy. For now, at least it means I can run pi-star 24/7 again, especially as I had to upgrade it by hand as it has missed a lot of the overnight updates. And it saves me having to run mains power into the loft.

I managed a couple of rather poor grabs from the ISS SSTV event of the 28th and 29th January. Nothing to write home about, my setup is not suitable being simply a loft mounted colinear. However, this one fragment was interesting because when received the ISS was over the middle of Poland. Not too bad for around 800 miles or so. In fact, I received another fragment after this... And two further grabs on the 29th, the first over the English channel and the second as it passed over Poland.

Still works fine... poor little dish all out in the cold of winter...

It's snowing fairly heavily here today and I wondered what effect, if any this would have on my QO100 reception. Very little it seems. There is no loss of signal strength when viewing the lower beacon, but the noise floor has raised a little. There's not a great deal on the dish but then it's pretty much vertical. There is a wedge of snow at the bottom of the POTY rain cover. Clearing the snow off made no noticeable difference to the signal. It's snowing less now and still nothing noticeable. I need to compare with a clear sky... which we had the next morning. There is actually very little difference, the noise floor appears better but it's very hard to say by how much and indeed if this is even real. The signal strength appears very slightly better. Without proper measuring methods it seems the snow and ice made hardly any difference.

A combination of things finally came together. I’ve never played with digital SSTV before, plus I had some time to fiddle about and wanted to see if I could decode some of the digital stuff from QO100. Finally, I received a couple of nice digital pictures of the Dakar rally from F6HA, neatly incorporating my previous main love of motorsport! My setup is far from perfect (read, a series of accidentally cobbled together bits): Windows 10 laptop running the excellent SDR Console and connected to my QO100 transceiver via Ethernet, audio mixer feeding from the laptop and to the Linux PC, and QSSTV on the Linux PC. There is a lot of noise in my QO100 setup that I need to figure out because it really messes up analogue SSTV and seems to have made these digital modes even more fiddly. This is probably not helped by the audio running round the shack. In an ideal world I’d have a decent Windows PC with two screens and a virtual cable. That needs to wait until we sort out what is to happen with an older PC desktop here as if it is to be replaced I will nab it and…