Radio and rails...

For some time now I had been running a radiosonde receiver based on one of the small Lilygo LoRa devices with a built-in display. It used wifi to connect to our LAN and thence off to its reporting platform https://sondehub.org/. Because it used an antenna in the loft it never did very much with regard to monitoring but it was a no-cost 'why not' type of thing. However, after some time now the display was dimming and it would often have issues if the wifi hub rebooted. So I really wanted a no-wifi solution and found one based on a Pi and an RTL-SDR dongle.The software and setup instructions I followed can be found at https://github.com/projecthorus/radiosonde_auto_rx/wiki and worked semlessly. The setup creates its own web server, by default at port 5000. After a few days of nothing it finally recorded two hits overnight: Not too bad for a 70cm Big Wheel in the loft. Looking at the data, for the first entry which is the one approaching Liverpool data was received when it was at 11,500m altitude down to 9,521m at 403.4MHz. The second trace out to sea was on 405.1MHz and from 19,670M to 25,349m at the end. The traces…

Since I got it the FTM510D has been mounted under the shelf above the monitors. While that was ok it meant the mic lead was always caught behind one of the monitors. Having tidied one bookshelf and moved things around moving the Portsdown left a space under one of the three screens. A space, I thought ideal for the FTM510D. But how to mount it neatly... A search for 3D prints for the radio resulted in mainly mobile solutions but I came across a comment on one aimed at an earlier model saying the dimensions should be the same. It seems the FTM150 has the same slidemount arrangement and dimensions. So, off to makerworld - https://makerworld.com/en/models/1181052-desktop-stand-for-ftm-150rasp-may-fit-others - and off to order more PLA because I had hardly any of any sort of black filament. Twenty eight and a bit hours later... my biggest and longest print to date. Anyway, it worked just fine. After trimming the bits the radio slots straight in. The model even has a slot to hang the mic, and it sits just right under the monitor. Four sticky feet to stop it sliding finished it off. Surprisingly all the cables were of sufficient length for the radio's…

While experimenting with various SDRs and antennas I have ended up with just far too much stuff, some of which will now be sold, either locally, on eBay or on Hamradiodeals. For VLF I am happy with the YouLoop and Airspy HF+ Discovery combination so the PA0RDT mini whip is going. The Behringer UMC204HD is also leaving as is the Heros VLF-LF up-converter. That sorts out part of the shelf above the monitors. The FT817 will also be sold on as will the FRG9600 - I just don't use it - the FT2D and FTM100D. So this means my SDR receiver kit is down to a managable amount: RSP2 for general use, RSPdx which has the QO100 NB feed, Airspy HF+ Discovery and Airspy R2.

I seem to be gathering 10MHz stuff for some reason - but there is a plan. The latest toy to arrive is this BG7TBL 10MHz / 1pps GPSDO which arrived very quickly from China via Aliexpress. The primary role for this will be to feed the 10MHz distribution amplifier which in turn drives a few bits of equipment, plus give a 1pps signal to the rubidium oscillator (just for fun really!). My previous 10MHz source was the DX Patrol GPSDO which has been retired. Now I need to arrange all this frequency stuff somewhere rather than it being spread about. It's a pity this and the distribution amplifier need a maximum of 12.9V so the make shack PSUs are out and I set up a 12V SMPSU (which seems RF quiet fortunately) specifically for these plus the 12V for the Winterhill box.

I have been running an ADS-B decoder here for many years now and feeding flightradar24. However, yesterday I got an email alert that the decoder was offline. it seemed ok locally as the status said it was connected but it was no seeing any aircraft. This was last night but there were plenty of aircraft near enough. On further checking via the flightradar24 website it seemed the maximum distance seen was just 2 miles. One aircraft took off from the local airport and the decoder did see it, but only for a short while. So, off into the loft. I swapped the dbv dongle. No change. I took the preamp out of curcuit. No change. I installed the latest fr24feed. No change. Hmmm. Then it was time for bed... This morning I checked the collinear using the TinyVNA and it showed it was fine. I swapped the antenna lead that came with the dongle for an adapter type. No change! Back to the software then. I have not changed the setup for ages, in fact not since I migrated the decoder from a Pi to a Linux box. And it was always fine until now. Shutting fr24feed and dump1090-mutability down…