[amsat-bb] Trouble with MMSSTV

[Steve Kristoff]

Hope you don't mind that I shared your email (below) on-list, but I think you gave me a clue as to what I'm doing wrong and I would like folks to see a good example if they need it. 

Your screen shows the single peak at 1200, then essentially nothing until the picture info between 1500 and 2300 , then down to nothing again. I also noticed that the little green signal strength (?) bar just to the left of the FFT display is quite low.
I think maybe I've just had the input level up too high. I've got signal in the FFT portion all the way from 1200 to past the 2300 and the green bar about 1/3 of the way up it's range. Would that be enough to throw off the sync?

I may be able to clean  up the signal just by turning down the volume.
All helpful comments and suggestions are still very welcome. 


Steve AI9IN

 
----- Original Message -----
From: Greg D (ko6th.greg at gmail.com)
Date: 10/07/20 13:54
To: Steve Kristoff (skristof at etczone.com)
Subject: Re: [amsat-bb] Trouble with MMSSTV

Hi Steve,

The SSTV signals from the ISS yesterday were kind of garbled.  Multiple
stations reported this, so it's not your (or my) station's problem.

Take a look at a video of a (good) pass on Monday last that I did for
our club:

https://www.youtube.com/watch?v=Z_SkJ8_mtA4

The FFT display should show the specific peaks in the signal around the
line sync on the left, and a separate band for the actual picture to the
right of it.  If it looks like an amorphous blob, that was the
interference we all heard.  Hopefully they'll get it sorted out upstairs
and we can grab a few more pictures today.  Next pass in just under an
hour here...

Greg  KO6TH