Please be all reminded that the transponder will have a big influence itself. Cannot give numbers due to NDA but rest assured, what we all currently see is really good by all means.
I can confirm it all. A colleague who observes the ISS repeater on http://erc-websdr.esa.int/ 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
.... Btw the Brazilian WebSDR is about 250 Hz higher than the PSK-beacon, see my previous message with screenshot.
Somewhat off-topic and just for fun: the accuracy of the Brazil WebSDR depends on the time of day. At night-time in Brazil, it goes off by more than 1kHz
Some of these SDRs use sound cards. These are not locked to GPS. An error of 130Hz in a sound card would be - shall we say - disappointing and quite obvious but it's possible. Meanwhile, does anyone know how to gold plate a Lily?
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.