Radio and rails...

M0RVB

SAQ 24/Dec/2025

Today saw the Christmas 2025 broadcast from SAQ. I set up three receivers to see if any could pick the signal up. These were as follows: YouLoop 1 (loft), Airspy HF+ Discovery, Mac SDR++ YouLoop 2 (loft), Heros VLF converter, SDRPLay RSP2, Linux SDRconnect PA0RDT miniwhip (loft) plus associated preamp, Behringer UMC204HD, Linux VLF-RX tools During the event the VLF-RX code refused to start because, I think anyway ALSA mixer had claimed all the interfaces - the error was that the interface was busy. I was running YouTube on that PC for the live stream. There was no copy, not even a trace of the signal via the RSP2, but the Airspy setup worked fine. Signal strength was well down on last time but still readable visually and audibly although the report I submitted was QSA 2 and QRK 3. The screenshot above shows the reception plus the difference between the LNA being off (lower half) and on. The YouTube video of the event can be found at https://www.youtube.com/watch?v=uSGQ0zR188Q

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M0RVB

Diminutive keyboard

I have been pondering leaving a screen attached to the Winterhill box and ahve now acquired a screen from a retired PC. It is destined to be hung on the wall but I also wanted a keyboard and mouse for the box. I have a spare RF keyboard and mouse but they tend to always be in the way. So I found this on Amazon, cheap enough to try and discard if no good: It is tiny and works fine. It would never replace a 'proper' keyboard most of the time but for this purpose it is ideal. I am not sure how long it will last as it does seem a bit fragile, in particular the power switch on the top does not seem to be of any quality. But time will tell. I can see this being useful elsewhere around the place. It looks to have most of the keys I would ever need including the Windows key (if one must!) plus backslash and that reverse aprostrophe that is sometimes missing. It misses that Pound and Euro but never mind.

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M0RVB

USB interference and Zigbee

Tonight none of the outdoor automated lights came on. On further testing the internal lights also refused to work. Odd, everything was just fine yesterday. I use Zigbee devices around the house with four devices controlling various outdoor lighting, two controlling dimmable internal lights and several devices reporting on room and heating temperatures. Two outdoor lights are all-in-one Zigbee bulbs, the others are diminutive units in various electrical boxes. All use 2.4Ghz Zigbee and all the lighting controllers are also Zigbee repeaters and so form a mesh. The whole lot is controlled by a Raspberry Pi with a Zigbee dongle, zigbee2mqtt, mosquitto and homebridge. This also integrates it into the apple stuff so everything can be controlled from the Apple Home app and/or Siri. Of coure the downside is there are few physical switches now so this was a problem I had to fix. I had no clue what was wrong. Rebooting made no difference. But a bit of searching suggested that USB3 devices can cause issues at 2.4Ghz. Remember from my previous post that I had attached a SSD to the server? Well, that alone made no difference but was a precursor to the issue. Today I had inadvertently…

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M0RVB

IT upgrades

After a life in IT you'd think I would be better at this stuff. Two things caught me out this week, both around the web server that runs this blog among other things. The first knocked it offline and I was unaware. The server is a dimimutive Lenovo ThinkCentre M92p and has 4 USB ports but none work which was annoying as I wanted to upgrade Lubuntu but really wanted a decent backup to an external device first. I had another of these systems with working USB ports so I swapped the hard disk between the two - the specs are essentially the same. All went well, apparently. I attached a USB SDD to use as a backup for the pending operating system upgrade. Then I noticed no incoming email plus I tried to access the blog from an external IP and it failed. Odd. No issues with accessing from the house LAN. Then I remembered having an issue with the PlusNet router but could not remember what so I logged into that to see if my memory would return. And it did. The PlusNet router helpfully follows MAC addresses rather than IP addresses so when I swapped the HDD…

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