[amsat-bb] Unusual ISS SSTV signal

[John Brier]

Two active. SSTV is in Russian service module. New radio doing crossband is
in Columbus module.

On Tue, Oct 6, 2020, 23:26 Greg D <ko6th.greg at gmail.com> wrote:

> Possibly, but the interference isn't at the audio level; it sounds more
> like an FM double to me.
>
> How many ham stations do they have up there?
>
> Greg  KO6TH
>
>
> John Brier wrote:
>
> Reports suggest two SSTV transmissions at same time.
>
> https://twitter.com/bobbylittle/status/1313665745734324225?s=19
>
> Crossband is totally diff setup in diff ISS modules.
>
> 73, John Brier KG4AKV
>
> On Tue, Oct 6, 2020, 23:04 Greg D via AMSAT-BB <amsat-bb at amsat.org> wrote:
>
>> That was my first thought, but I'm presuming they're running from
>> separate power sources, and using separate antennas, in different
>> modules of the Station.  If anything, the interference would be the
>> reverse, with the SSTV desensing the x-band repeater's uplink.
>>
>> Also, my audio sounds rather different from Loren's, so perhaps
>> different (or degrading) situations?
>>
>> Greg  KO6TH
>>
>>
>> Gary wrote:
>> > A local told me the ISS repeater was on the air. Is that possible in
>> conjunction with the SSTV?
>> >
>> > 73,
>> > Gary "Joe" kk0sd
>> >
>> > -----Original Message-----
>> > From: AMSAT-BB <amsat-bb-bounces at amsat.org> On Behalf Of Greg D via
>> AMSAT-BB
>> > Sent: Tuesday, October 6, 2020 9:38 PM
>> > To: Loren M. Lang <penguin359 at gmail.com>; AMSAT BB <amsat-bb at amsat.org>
>> > Subject: Re: [amsat-bb] Unusual ISS SSTV signal
>> >
>> > I just heard something even weirder here during the just-completed
>> 02:04z pass here in CM98.  3 images during the pass, the first two totally
>> wiped out.  The third started off just fine, then the interference started
>> in.
>> >
>> > I captured the screen and audio for the second and 3rd images here:
>> >
>> >
>> https://www.dropbox.com/s/jzlp9jzs4k29sy1/ISS%20SSTV%20Pass3-2020-10-06_19.08.39.mp4?dl=1
>> >
>> > I'm no where near where Loren is, so it's unlikely to be local.  This
>> is with the same equipment and setup as two passes yesterday, which were
>> totally clean.  The 8pm (PDT) pass yesterday was recorded for our local
>> club, and can be viewed here:
>> >
>> > https://www.youtube.com/watch?v=Z_SkJ8_mtA4
>> >
>> > Thoughts?
>> >
>> > Greg  KO6TH
>> >
>> >
>> > Loren M. Lang via AMSAT-BB wrote:
>> >> During one of the SSTV transmissions today, I heard an unusual signal
>> >> overlaid on top of the regular SSTV signal. It started just after the
>> >> original SSTV signal, and was initially quite strong, but eventually
>> >> lost out to the regular SSTV signal. It sounds similar to SSTV, but
>> >> not quite the same. This started at 2020-10-06 02:54:32Z. You can hear
>> it here:
>> >>
>> >> https://www.dropbox.com/s/abcizkoly8rn1ij/funny-sstv-signal.mp3?dl=0
>> >>
>> >> You can see the waterfall during the initial decode here:
>> >>
>> >> https://www.dropbox.com/s/dxmy4rhruiit84v/funny-sstv-signal.png?dl=0
>> >>
>> >> It does look like a separate signal on top of the original SSTV signal
>> >> and it looks more centered on 145.800 MHz than the Doppler shifted ISS
>> >> transmission which makes me thing it might be terrestrial, but I have
>> >> no idea where it would be coming from. It definitely looks like it was
>> >> targeting 145.8 and it sounds SSTV-like. The signal poped in several
>> >> more times as can be seen in this waterfall:
>> >>
>> >> https://www.dropbox.com/s/gwh4h4b1d8qtnbv/funny-sstv-signal2.png?dl=0
>> >>
>> >> Any ideas what this came from?
>> >>
>> >> Here's the image I received during that pass:
>> >>
>> >> https://www.dropbox.com/s/j11wj6yo9s2ceg9/sstv-202010060311.png?dl=0
>> >>
>> >> I do have the raw baseband signal if anyone's interested.
>> >>
>> >> -Loren
>> >> K7IW
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>> > _______________________________________________
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>>
>> _______________________________________________
>> Sent via AMSAT-BB at amsat.org. AMSAT-NA makes this open forum available
>> to all interested persons worldwide without requiring membership.
>> Opinions expressed
>> are solely those of the author, and do not reflect the official views of
>> AMSAT-NA.
>> Not an AMSAT-NA member? Join now to support the amateur satellite program!
>> Subscription settings: https://www.amsat.org/mailman/listinfo/amsat-bb
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>
>