Unusual ISS SSTV signal


Brad Smith
 

On the 18:08 pass of the ISS, no SSTV signal was heard. 

Sent from Brad's iPod

On Oct 6, 2020, at 10:51 AM, Clint Bradford via groups.io <clintbradford@...> wrote:

I would rather be positive, and NOT think it was "malicious" in nature. But it does 
seem to be "local" to you.

And as with any "jammers," just don't acknowledge them nor try to contact them 
on the air ...

Clint


Max White
 

If it is anything like the idiotic, mental cul de sac, G3 callsign/old duffer, who started talking to his mates on the ISS repeater downlink 'that it has now gone over and here are the times for tomorrow' - when it was still descending into the East from Zenith - nothing surprises me. Complete Moron!

73 Max/M0VNG


From: Work-Sat@groups.io <Work-Sat@groups.io> on behalf of Clint Bradford via groups.io <clintbradford@...>
Sent: 06 October 2020 16:51
To: Work-Sat@groups.io <Work-Sat@groups.io>
Subject: Re: [Work-Sat] Unusual ISS SSTV signal
 
I would rather be positive, and NOT think it was "malicious" in nature. But it does 
seem to be "local" to you.

And as with any "jammers," just don't acknowledge them nor try to contact them 
on the air ...

Clint


Clint Bradford
 

I would rather be positive, and NOT think it was "malicious" in nature. But it does 
seem to be "local" to you.

And as with any "jammers," just don't acknowledge them nor try to contact them 
on the air ...

Clint


AF7ZA
 

Clint. Is it possible someone was attempting to TX interference from ground ?

On Oct 6, 2020, at 8:29 18AM, Clint Bradford via groups.io <clintbradford@...> wrote:

I have talked to others who worked your pass. I think your issue is local, and not directly related to the ISS' equipment.

Clint


Clint Bradford
 

I have talked to others who worked your pass. I think your issue is local, and not directly related to the ISS' equipment.

Clint


 

Yes, luckily the mysterious signal only occurred towards the beginning
of the transmission, but everywhere you see green lines around the
image is where it happened. That giant green bar was solidly the
extraneous signal.

-Loren
K7IW

On Tue, Oct 6, 2020 at 1:03 AM Clint Bradford via groups.io
<clintbradford@...> wrote:

But your image is almost perfect ... didn’t listen to audio yet ...


Clint Bradford
 

But your image is almost perfect ... didn’t listen to audio yet ...


 

I sent a copy of this to AMSAT BB, but was curious if anyone here
might have a clue.


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