[amsat-bb] SSTV on Linears

[Mark D. Johns]

PLEASE do NOT use FM on a linear transponder!!!

There are very good reasons why there are FM satellites and there are
linear satellites. FM on a linear passband screws things up in a number of
ways, as can be heard whenever a linear has Mexican taxi cabs in its
footprint.

Please, just don’t even suggest such a thing.

On Tue, Dec 31, 2019 at 11:30 Scott via AMSAT-BB <amsat-bb at amsat.org> wrote:

> Heard you but was caught off-guard... I assumed you would TX on FM, but it
> seemed to be the normal USB downlink.
>
> Won't be around for the upcoming CAS-4A pass, but have fun & good luck!
>
> -Scott,  K4KDR
>
> =======================
>
> On Tue, Dec 31, 2019 at 11:13 AM Roy Dean via AMSAT-BB <amsat-bb at amsat.org
> >
> wrote:
>
> > >
> > > I did some SSTV years ago via AO-40. Really fun. But with a LEO
> > > satellite, you will need to be actively adjusting for Doppler shift in
> > > real time, as SSTV is frequency sensitive. You might try some of the
> > > faster modes, especially since a pass is over in just a few minutes.
> Greg
> > > KO6TH
> >
> >
> > I just did a dry run with my station, and think I'm ready to try an
> actual
> > pass.   I will be operating in "Robot36" mode on CAS-4B (17:00z) and
> CAS-4A
> > (17:30z) this afternoon as  first attempt.   I plan on shooting for the
> > lower portion of the 2m passband (going to target the lowest published
> > downlink frequency).  I will likely announce several times prior to first
> > transmitting to fine tune.   My test image is very simple black and white
> > call/grid.   If anybody hears it, please feel free to respond with an
> image
> > (short notice, I know), or voice.   If you don't hear me, then something
> > came up to pull me away from my computer or I simply can't get in.
> >
> > --Roy
> > K3RLD
> >
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-- 
***Sent from Gmail on iPhone***
Mark D. Johns, Ph.D. K0JM
Professor Emeritus of Communication Studies at
Luther College, Decorah, Iowa USA
Now residing in Minneapolis, Minn.
------------------------------------------------
"Get the facts first. You can distort them later."
---Mark Twain