Radio and rails...

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…

The latest addition is a KiwiSDR (see http://kiwisdr.com for details). This comes basically as a black box which just plugs into an RF antenna, a GPS antenna (puck-type supplied), a 5V PSU (I purchased their recommended one) and an Ethernet port. It boots, acquires an IP via DHCP and announces itself to the world. And I mean that literally - well, ok it doesn't shout, but it does gain a proxy address which is accessible from the Internet, not just locally. The kit I have came from Martin Lynch who had them in stock and it arrived next day. The setup instructions (http://kiwisdr.com/quickstart/) are easy to follow. Of course, the very first thing to do is change the admin password. Other than that I configured it to use my own URL as well as the proxy they provide, setting the relevant rule in the broadband router to allow access to port 8073. I am still customising it and as yet the antenna connected is a YouLoop which fairs better when connected to the Airspy HF+ Discovery. I have a Cross Country Wireless loop to set up which should provide for a better reception across HF. The KiwiSDR works from 0…

One of my interests, of which there are far too many for me to ever get anything done, is VLF. I regularly receive the broadcasts from SAQ and having a bit of time after the Christmas holidays and before having to get to grips with the garden ready for spring I downloaded Opera v1.6.5 by EA5HVK of VARA etc. fame. It can be found via https://rosmodem.wordpress.com/ I didn't (yet) find a lot of information but there has been a bit of chatter on the VLF email groups of late and the software basically needed very little setting up - however I am receive only yet so time will tell. Anyway, it installed under Wine on one of the Linux boxes and only offered me the internal soundcard for audio, which is what I needed anyway. The only antenna I have which is suitable for VLF reception is the YouLoop in the loft. This works well with the Airspy HF+ Discovery and SDR++ on the Mac for reception of SAQ and the plethora of 'interesting' signals down there. So I questioned that Opera would work if I simply piped the audio from SDR++ into the Linux PC - it works with…

The first new (to me) toy of 2026 is a Yaesu G5400B Az/El rotator and controller. This is another thing I have been looking for and this came at a reasonable price. Not yet tested as it needs cables which are made to measure... I've no idea even where to mount it! I can see it ending up on a short mast somewhere up the garden with a couple of Yagi antennas on for 2m and 70cm for satellite work. EME has always been a dream and this has potential and for me EME is more something I want to do but not do all the time. Plus it's hard! So, above is is the two parts of the rotator itself, azimuth on the left and elevation on the right. And the controller is shown below. The unit is 240V powered and once I get some cable I will test it.