Observation 1474669: OSCAR 7 (7530)

Regarding Observation 1474669
@4:08 I hear some strange “clicking” noise - don’t know what this is !
@4:56 I hear “cq de NS3L” in morse code many times (capital letters are mine)


I think the clicking noise is just the satnogs CW demodulator trying to decode a noise signal as CW. In the waterfall it looks much wider than CW. The NS3L (a local operator to me) seems to just be an effect on the CW beacon as Steve’s CW is actually higher up in the transponder (probably just a power effect on the electronics).

Does the AO-7 beacon even work anymore?


There are reports that OSCAR-7 mode B (U/V linear inverting transponder) is still alive on:


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@K3RLD Roy, you mean that the “clicking” noise I hear is from the satnogs CW demodulator ?
I thought that the audio of an observation is the audio that the originating satnogs station had received and uploaded.
Can you elaborate on that please ?

The audio of NS3L calling CQ @4:56 is not that clear (RST 535), but I hear him.

Laurent VE2WI

Yes, it has been on for quite some time, and I’ve made contacts on it. What I was asking is if the beacon still works. I’ve never seen it on the downlink when working the SSB transponder.

What I mean is that the satnogs client is recording a very small bandwidth of frequency (I don’t actually know how wide it is) as recording that as CW audio. However, when a wider signal (or a wider noise signal) encroaches on that bandwidth (but is not centered in it), you end up hearing strange noises that don’t necessarily sound like classic CW tones. I think that is what the clicking is.

It’s not clear because the satnogs client is not “listening” at the correct frequency. You can actually see NS3L’s CW signal off to the right side by a few kHz. I believe that what you are hearing is an image of his signal affecting the transponder downlink. This can happen on AO-7 when users (especially CW users) operate at higher power.