On Tue, 27 Dec 2005 20:53:54 -0600, "Richard Fry"
wrote:

"Gary Schafer" wrote
However if the TV video signal was an FM modulated signal rather than
AM then the sound sub carrier would not be visible without the main
video carrier if it was generated as a sub carrier.
The same happens with an FM broadcast SCA sub carrier or the stereo
sub carrier on the main signal. The main signal must first be
demodulated in order to demodulate any sub carrier.
_____________

The r-f spectra of TV aural signals and FM SCAs are standalone entities.
Each may be fully demodulated by a suitable FM receiver capable of tuning to
that r-f spectrum. No "main" carrier is needed. Given, this isn't the
conventional practice -- however it would be possible to do.



It may be "visible" but it is not a standalone signal like a TV aural
signal is. With an SCA signal there is more than one side band on the
main carrier involved. With TV aural there is not.

73
Gary K4FMX