I'll give you my take on it. My initial report looks like local terrestrial interference because the waterfall seems to show a very strong signal centered on 145.8 over the slightly doppler shifted SSTV signal as can be seen here:
https://www.dropbox.com/s/dxmy4rhruiit84v/funny-sstv-signal.png?dl=0
I would like to think it was non-malicious as that doesn't seem likely, but it coincided very closely to the start of the next SSTV transmission and was nearly the same bandwidth sounding SSTV-like, but not quite. Maybe the sound was due to some mixing of the two signals, but I don't think that would produce the sound I heard. The second issue started when the SSTV transmissions went silent around 15:00 UTC on 10/6 as can be seen by all the read reports here:
The first block of red reports was due to the Cygnus docking on 10/5, but it came back later that day well before they said it would resume. It was up for several hours and went silent on 10/6 for a reason that I don't know yet. When it came back, the pictures were distorted for several passes I tried. This time, it looks like the signal itself and not interference. Maybe the audio was mis-adjusted and distorting, but I had near perfect condition and even did some post-processing and doppler shift correction with the raw, baseband signal after the fact and it still produced an ugly image. I could even see the ISS during the pass and visually track it with my handheld Yagi. This was 02:00 10/7 UTC. Here's the best I could get out of that pass:
https://www.dropbox.com/s/a3ibnks6ionwwt2/bad-sstv-202010071920.jpg?dl=0
The next day (for me) at 18:30 10/7 UTC, It was much improved and I captured this on my phone directly without any post-processing or doppler shift correction:
https://www.dropbox.com/s/39feej142tn9gcd/20201007_133152.png?dl=0
I've captured multiple images on several passes since with similar clarity.
-Loren K7IW
On Wed, Oct 7, 2020 at 6:26 PM Greg D via AMSAT-BB amsat-bb@amsat.org wrote:
Good passes here, too.
So, with the dust settling on this little adventure, do we know what happened? What rigs were in use for what roles? Where was the interference coming from?
Greg KO6TH
John Brier via AMSAT-BB wrote:
Any chance you had dual VFOs and one tuned to 437.800 as well as 145.800?
On Wed, Oct 7, 2020 at 1:36 PM Vince Fiscus, KB7ADL via AMSAT-BB amsat-bb@amsat.org wrote:
At 11:57 AM 10/7/2020 -0400, you wrote:
Was it a female russian voice? They have a system that announces the locations they are passing over and it gets into SSTV transmissions somehow/sometimes.
No, Just a number of english speaking U.S. OM's making fm contacts. The sstv was louder than they were. KB7ADL
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Sent via AMSAT-BB@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
Sent via AMSAT-BB@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