Radio and rails...

A minor project requires a metal enclosure so I got one off eBay. I have a 5V PSU and three Pi's to install to keep these all nice and tidy. The enclosure is sized to take the PSU and has ample room for the Pi's and a fan. The enclosure arrived and is surprisingly well made for the price. It has plastic surrounds front and back. The front and rear panels are held with screws and the top comes off. There are two metal runners inside to maintain the structure with the top removed. Not a bad little case. The only odd thing is the description. Apparently the features of the case are 'surface mounted', ok I expect this means 'sat on a desk', and 'underground electrical enclosure switch junction box'. Not so sure on that one!

After some fiddling I now have a decent amount of signal coming down from QO100, but also questions. The azimuth was already correct and I had adjusted that to maximum signal strength on a TV channel with a GT Media V8 Finder. But the elevation is numerically wrong, or the markings on the dish are wrong, which is more likely. Fiddling with elevation got the strongest beacon signal at about 26db and 26 degrees marked, but the AMSAT info says it should be around 23 degrees at my QTH. Mind you, for all I know the garage wall is not perfectly vertical! All SSB signals look good now except for one or two that are difficult to hear. However, having got that far, no adjustment to the position of the POTY in the arm or its skew make any noticeable difference, so I've left that one. Also, when transmitting a tone from SDR Console it actually peaks higher than the beacon so I had to reduce the drive appropriately. An SSB signal test showed very poor audio and no adjustments in SDR Console got it to where it needed to be. Turning the mic gain up in Windows itself cured…

Since I built the Minitiouner I've had nothing to test it with except a quick test on the Astra satellite to prove it actually worked. Not any more. I now have a Portsdown ATV transmitter setup thanks to a recent advert for one for sale (saved me having to get all the bits). No PA, no antennas or anything else here yet, but I did at least manage to send a test card from it to the Minitiouner over 23cm and at the grand distance of 6 inches. It all needs a nice case yet but it's a good start. This might even persuade me to bung my 23cm yagi on the chimney and see if I can actually receive GB3YT - it's not too far away but there is a house in the way.

Scary stuff. The RSGB announced (yesterday I think) that the full licence exam will be available to be booked online from today. I've booked for mid-november to give me time to actually learn this stuff... (yeah, I know... probably not that bad though because I have an electronics background so it's more a matter of making sure I don't miss anything daft).

Got myself a Heil headset for the laptop as the built-in mic picked up room noise. So, I figured it was time to try a QSO on QO100 even with the floating (frequency wise) Pluto. And - success! I had a short QSO with a German station. Just waiting for some small signal diodes to arrive before I glue the GPSDO output to the Pluto. There is a modification that involves removing the 40MHz TCXO and connecting an external source but the Leo Bodnar GPSDO output is 3.3V, too much for the chip in the Pluto. The mod involves two diodes in antiparallel to earth, plus a capacitor between the Pluto chip and the diodes, and another between the diodes and GPSDO. Hopefully that will work and the surgery on the Pluto does not consign it to the scrap pile! The GPSDO I have has two outputs, one 25MHz to the LNB, and one 40MHz for the Pluto. I still need to sort the dish as signal strengths are still below where I expected. I am also concerned at the filter/pre-amp because it does not draw as much current as it is supposed to - it works but I wonder…