Radio, railways, stuff...

Very clear reception of the SAQ 100 year anniversary broadcast today, 1st December 2024. This is the first time I received SAQ despite previous attempts. I had two setups running in the hope to at least see something. SDRconnect was running on the Linux box connected via a Heros upconverter and a mini whip in the loft, and SDR# was running on the Windows 10 PC connected to the Airspy HF+ Discovery and a YouLoop antenna in the loft. The YouLoop was oriented towards SAQ at about 62 degrees from here. The mini whip saw nothing but as I mentioned previously it looks to have a serious drop off below about 20kHz. But the Airspy + YouLoop combination worked flawlessly. I saw the carrier appear at aroudn 09:45 UTC as they were switching everything on, followed by a loop of VVV SAQ. Then, at 10:00 UTC came the anniversary broadcast itself begining with CQ de SAQ. It was quite neat to see the gentleman on the key at SAQ and see the morse via the SDR. You can see the morse trail from SAQ on the image above, not a great deal above the noise floor but sufficient to read the morse as well as see it. While the broadcast was continuing I had time to fiddle with the settings in SDRconnect but never saw anything. Not the fault of the software of course, it is all down to the antenna. I did not attempt to swap antennas between the two setups as I did not want to miss any of the action.

I now have two new toys, an Airspy HF+ Discovery SDR, and an Airspy YouLoop antenna. Plus I already have a SDRplay RSPdx which was purchased some time ago. The initial aim of these is to hopefully receive signals from SAQ’s 100 year anniversary broadcast. The YouLoop is in the loft and connected to some RG213 coax back to the shack. That coax was feeding the random wire for HF but as I now use the external wire the coax was pulled back and shortened. It is entirely passive so does not require any voltage supply and has a range of 10kHz to 30MHz plus VHF up to 300MHz. There is also an IP35 mini whip which was acquired some years ago and as an active device needs a supply which is achieved by a bias-tee fed from the 12V shack PSU. That antenna has a range of 10kHz to 30MHz and is fed via some RG58. The YouLoop is pointing, quite by chance at the MSF 60kHz time signal transmitter. The IP35 is largely omnidirectional. The Airspy covers 0.5kHz to 31MHz and 64MHz to 260MHz whereas the RSPdx covers 1kHz to 2GHz with no gaps (200MHz on the BNC port). As my current use for both is VLF work the ranges are ideal. Swapping the antennas between the two backs up my previous findings that the mini whip rolls off below 20kHz, rather unfortunate given SAQ is on 17.2kHz. The response of the YouLoop is flat across the spectrum which is not surprising given it is passive. The complete setup is as follows: Both setups receive the MSF (60kHz) and DCF77 (77.5kHz) time signals perfectly well. There was some very annoying interference on the AIrspy setup but this was traced to connectors. I had reused coax that was originally connected to the HF random wire and had a number of clip-on ferrites. Removing those resulted in me discovering the patch lead I was using was solid cored and the BNC connector had worked loose, plus there was a vibration issue affecting signal strength. Removing the coax from the BNC patch panel and attaching the Airspy directly to it cured the interference and shows the Airspy + YouLoop to be a superior setup displaying nice clean signals across the band. Of course, comparing these two setups in this was is extremely subjective and that was not my aim. The aim here is to hopefully copy the SAQ 100 year anniversary broadcast on 1st December 2024.

Things happen slowly here. Very slowly... I finally got some coax fed out through and air brick and connected the external random wire up that slopes down to the workshop so I cna use it without needing to open the shack window and feed a cable out. Experimenting, the tuner was happy on 6, 10 and 12 but less so on 15 with the rig seeing a SWR close to 3. It would tune 30m too but knocked the GPS signal to the clock off, clearly RF in the shack. I did not try lower because I then realised that, like a twit I forgot to fit the 1:1 unun! With the 1:1 unun installed outside the tuner was happy-ish with 15 but now not 12. Oh well. And it refuses to get below a SWR of 3.0 on 30m and is quite bad on 40m which is annoying, but on the plus side tuning does not knock the GPS clock off! I suspect I have managed to get an awkward length of wire so I will shorten it later on and expreiment further. Surprisingly, it is happy on 80m and it will tune 160m but that did knock the GPS clock off and I am amazed the place isn't on fire! That was just a very quick experiment and I am under no illusions of the futility of such a short bit of wire on that band, or, indeed on 80m. In any event my FT8 signals at 25W were picked up on various bands well across Europe and into the US and Canada with reports via pskreporter broadly similar to the loft long wire, although of course this is extremely subjective especially with compromised bits of wet string. But reports are reports.