[amsat-bb] AO-7 broadband noise in passband.

Paul Stoetzer n8hm at arrl.net
Thu Jun 1 04:16:18 UTC 2017

They are definitely internally generated. Someone who's been around longer
might be able to say if they've been there since the beginning or if
they're possibly the result of intern circuit degradation of some type.

Incidentally, the noise peaks coincide with the most sensitive parts of the
transponder. The middle is the weakest.


Paul, N8HM

On Thu, Jun 1, 2017 at 00:02 Bill Bordy, NJ1H <nj1h at comcast.net> wrote:

> I have been observing AO-7 quite a bit lately and I have noticed three
> broadband humps in my panadapter display. I also see these in W5RKN
> panadapter captures at:
> https://drive.google.com/file/d/0B-Jez46MB5RaMzV0RlhmWHNWcjg/view?usp=sharing
> This confirms these are being transmitted from AO-7. They disappear
> immediately after the mode switch in his captures. I also observed this
> today at 31 MAY 2017 about 19:03 UTC during a mode switch.
> Does anyone have an explanation of why these occur? The obvious might be
> some sort of signals on the uplink. Has anyone identified if these
> signals occur throughout the world or just in specific areas. If you
> look at these, a large part of AO-7's power output is being used to
> transmit the broadband humps.
> 73,
> Bill
> NJ1H
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