[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

RE: Satellite ATV (was...)



Art Feller said:

> FYI:  Here in the USA/FCC's Laboratory Division, back in the 1940's,
> analog FM television was tested along with AM/VSB with both using
> 6 MHz  channels.  FM worked quite well.  Indeed, to my eye reviewing
> the photographs from receivers of the day, FM worked better than
> AM/VSB.

> I'm still not sure why AM/VSB was chosen.  Curious.

> Anyway, it's a tidbit from history.  Hope you find it interesting.

6 MHz is REALLY narrow band for FM TV.  What is considered "Narrow band" FM
TV is 4 MHz deviation which results in a 17 MHz wide channel.  This does
result in a picture that is better than AM/VSB.  Wide band TV is 11 MHz
deviation and uses a 40 MHz wide channel - this is what C-Band analog
satellite TV uses.

73
-------------------------
Jim Walls - K6CCC
k6ccc@amsat.org
http://home.earthlink.net/~k6ccc/
Ofc:  626-302-8515    FAX:  626-302-9999
AMSAT member 32537 / WSWSS member 395
----
Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org



AMSAT Top AMSAT Home