Goonhilly WEB-SDR is not on Frequency ?!

  • I can confirm it all. A colleague who observes the ISS repeater on reports me, that he heard the repeater downlink on 437.825 but 437.800 MHz. Btw the Brazilian WebSDR is about 250 Hz higher than the PSK-beacon, see my previous message with screenshot.

    What is the problem now ? Long live vintage radio ;)

  • Hi,

    100 hz or 130 hz is definetly too much, i am operating a web sdr (from Pieter-Tjerk@Twente) as well.

    The BATC uses GPSDO locked AirSpy SDRs.

    If the operator sets the wrong offset in the linux config, than the values are not exact.

    My own local station is all the time 100% on frequency with 2 Leo Bodnars.

    Just the gravitation doppler shifts +/- 30Hz, which can be averaged.

    73, Mike

  • For those wondering, the goonhilly crew is having bad luck and is now reporting issues with the GPS antenna. The GPSDO is still stable but a few kHz off. Maintaining some repeater sites myself, I feel for the crew because Corona generally makes access to these sites very complicated if not impossible. The webSDR is still very usable but keep in mind it is a few kHz off.

    Status info is given on the info on top of the page (yup, the info I skipped too)

    This actually gives an interesting side effect. When looking at the upper beacon, I always heard an extra carrier (have the same problem in my setup). This is probably related to the reference frequency sent to the LNB. Because the reference is now slightly off, the reference harmonic and the beacon signal are now on different frequencies. You may want to study the upper beacon while this situation persists.