Observation 126345: XW-2D (40907)

Regarding Observation 126345

An op tries to stay on frequency +10kHz above center!?

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There are 1000+ other good observations of the same satellite in the network form all over the world. Use them to draw a conclusion :wink:

The lines of constant frequencies should be parallel to one of the constant frequencies sigmoids
(there is one on the left). So the continuous lines should go on the right and discontinuities on the

After that, I do not see neither.

and the slope of the lines are about constant during the whole time.
So I would vote for a doppler.
At least not a doppler with something on earth

Don’t forget that we have a global network!

When we receive the same signal in the US, Europe and Australia, and even at different times, we can safely assume that the signal is generated by the satellite

the signal is generated by the satellite

True. But: WHAT is it? I cannot hear this signal in Audio. Telemetry in CW?

From https://db.satnogs.org/satellite/40907/ you can see that there is a linear transponder with a downlink between 145.860 MHz - 145.880 MHz which I think explain what we see.

Audio is limited near the center frequency and probably for CW script is less wide than in the default fm script. This is probably why you can not hear it.

The XW-2 satellites have an FSK beacon, a CW beacon and a linear transponder. I don’t think this is an intended signal, just a spurious emission.

XW-2 band plan:
XW-2CAS-3-Sats.pdf (442.3 KB)

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@DE8MSH your suggestion for a “CW Analysis (DE8MSH)” transmitter has been approved. An unfortunate side effect is that it is now the default transmitter and people who are not paying attention are scheduling with it. There are now quite a few observations for your analysis :wink:

I am renaming it to “Spurious transmission” hoping that people will notice and avoid accidental scheduling with this transmitter. When you are done with your analysis we can disable it again.