Getting ready for the December SAQ broadcast

M0RVB

I am making a better effort at picking up the SAQ broadcast due on the 1st of December. I now have a VLF mini whip (no idea where it came from now!) up in the loft fed via a bias-tee and connected to a Heros VLF converter which takes 0 to 500kHz and converts it to 4,000 to 4,500kHz. Although the loft is a poor location for this it is a lot better than in the shack. the Heros is connected to an RSPdx on it's BNC port and this is connected to the Linux PC which runs SDRconnect as a server. Reception is via SDRconnect on the Mac.

So far, so good, I can see the MSF and DCF77 time signals on 60kHz and 70.5kHz respectively plus a ferw other peaks, at least some of which correspond with known transmitters.

A screenshot of SDRconnect showing VLF frequencies converted to 4kHz.

Getting the settings right is a fiddle. The above photo has the base set low and the red line is where SAQ should be. But there is quite a rolloff there so hopefully the signal will be sufficiently strong to receive. The antenna is supposed to work down to 5kHz and the Heros is specified as <5 to 500kHz.

Adjusting the base and also gain settings makes for better peaks but is worse down at 17.2kHz.

A screenshot of SDRconnect showing VLF frequencies converted to 4kHz.

So I am a bit worried that I will miss the broadcast, but still hopeful!

 

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