Radio, railways, stuff...

Well that's a first for me. A dead Pi, or rather a dead SD card. I have a RPi 2 in the loft connected to a DVB-T dongle and ADSB antenna which sends data to FlightRadar 24. It's been up there doing its thing for ages, but last night I received an email from FR24 that it had stopped sending data. As it turns out that was a very useful email because everything else was running fine. It also logs temperatures from three 1Wire temperature sensors on the central heating pipes. As these are underneath the location of the Pi in the loft it was easier to run a wire down for the 1Wire sensors than cobble together another Pi and find a home for it away from the heat of the water cylinder and pipework. That logging and my network monitor indicated that all was apparently well and I had not noticed the FR24 status data indicated that the ADSB feed was down. The Pi is fed via a PoE supply as I didn't want a wall-wart and mains socket up there and it makes it easier to reboot. I logged into the Pi fine ad rebooted it from the command line to see if that cured the ADSB issue in case it had simply lost the USB-connected dongle. But it never came fully back and would not even open the ssh port. It did respond to ping. Power cycling made no difference and by this time it was midnight. This morning I made a new SD card and got it all back working (actually better as the card is the latest o/s now and the FR24 feed also has the MLAT option built in). So, some interesting and annoying observations: The Raspberry Pi website now has a download package for the Mac which makes creating a new SD card image a doddle. Simply download and run it, stuff a blank SD card in and choose the options and wait. Don't use the HDMI monitor, mouse and keyboard off your desktop PC when trying to get a Pi to work if you need to use said desktop PC at the same time! Yeah... No matter how good your backups, if you cannot remember the name of an important file the backups are useless by themselves. D'oh. But most importantly remember that you can mount a Pi SD card on a Linux box (and no doubt other systems) and access the files if the card still mostly works like mine did. Fortunately there were only two things on this Pi, the 1Wire code which is a five-line bash script and the FR24 package which basically installs itself from their download site. QED.

My current issue with receiving QO100 (not got round to transmitting yet, baby steps!) is where to put the 1.2m dish. I don't really want it on the wall or at the front of the house as it's grey and huge. It can't go at the front of the workshop due to an apple tree and if it goes anywhere on the garden we'll fall over it. I'm currently thinking that the bit of land we have at the back of the garage will do and I can easily run the cables into the workshop from there, or even put all the RF side of things in the garage. But with no cable route from the garage to the shack (aka the little bedroom) it seems I will need the SDR co-mounted with the RF bits and run it via Ethernet or Wifi. Of course, there is also the wall outside the little bedroom but then we'd see it every time we gaze over at the moors... Update 11/April/20 I've worked it out. There is room at the front of the workshop to the side of the apple tree where the dish will see the sky if it's up maybe 4 foot. The mount I have is 3 foot so my 'plan A' is to get a 4 foot 2" pole and an extender clamp, set some concrete (whenever we're out of lockdown) and get the dish up. This makes it a doddle to feed the cables into the workshop.

Finally I had time and reasonable weather to have a go at receiving QO100 today. I know I can receive the satellite because I've used my GT Media V8 and managed to resolve the TV channels. No home for the dish yet so it lives in the workshop between fiddles. Anyway, today was a bit of a comedy of errors but did result in success. First off, dish out, LNB in and aligned to the satellite. All good. I replaced the LNB with the POTY and got absolutely nothing on the V8. So I remembered I need the external 25MHz source so grabbed my Leo Bodnar GPSDO and the Windows laptop to make sure it was set up. Success, I can see the TV again. Next was to set up the bias tee, PSU and cabling, the SDRPlay RSP2 and the SDR on the PC. After a bit of fiddling I did manage to see traces but I have yet to investigate the SDR software on Windows so it was off back indoors for the MacBook. Note to self: remember to learn how to use software before you need to actually use it! The MacBook and CubicSDR proved the setup. I managed to decode a couple of SSB transmissions and decode the morse on the band edge beacon: "HI DE QO100 QRA DK0SB". Anyway, here is the lash-up. The signals were quite weak and clearly I need to do some adjustments yet but that really needs to wait until I fix the dish somewhere.