????
Is there such a thing as a TV broadcasting service on SW?
One that is not SSTV (Slow Scan TV) -- but some modern digital equivalent
based on H.323 or MPEG...
????

Not that I know of.

Bill, N5NOB

http://CBC.am/ wrote:
????
Is there such a thing as a TV broadcasting service on SW?
One that is not SSTV (Slow Scan TV) -- but some modern digital equivalent
based on H.323 or MPEG...
????

I don't know of any.

High-speed digital modes tend to have severe problems with the multipath
propagation common on shortwave. You can engineer modulation modes
that'll work on SW, but H.323 isn't one of them.
--
Doug Smith W9WI
Pleasant View (Nashville), TN EM66
http://www.w9wi.com

"Bill Hennessy" ) writes:
Not that I know of.

Bill, N5NOB


I'm sure no broadcasting.

But after slow scan was invented in the late fifties, it didn't open a certain
level of exploration. I remember reading an article from about 1963 or so
in 73 about sort of a medium scan system. I forget the details, but if it
had been allowed, it could have fit in the top 2MHz of the ten meter band.
I don't think it took up 2MHz, but there was hope of trying it up there (as
it was relatively unused, and that was the only HF band that did have space
for wider signals). A picture was sent at a faster rate than slow scan,
yet not at the rate of a full TV signal (and not the bandwidth either).
I can't remember if it was fast enough to convey some movement. I think
they may have used something like this for signals from manned space flights
at one point; I can remember seeing some stuff that had a jerkiness that
was not in full scan tv signals.

Michael