[BC] Re: Sub-Carriers

[DHultsman5@aol.com]

In a message dated 7/24/05 1:49:14 P.M. Central Daylight Time,  
broadcast-request at radiolists.net writes:

A  (sub)carrier is used when generating the AM sidebands of the L-R and color 
 
signals, but the (sub)carrier itself is suppressed from the output  waveform. 
Only the sidebands are there.

Proof of that is seen by  observing the composite baseband spectrum of either 
signal when the L-R or  chrominance input waveform to the encoder is zero. 
This occurs for stereo  FM when L=R (i.e., monaural), and for color 
television when there is no  color in the scene (i.e., monochrome video).  In 
both cases, there is  no subcarrier signal present in the composite spectrum 
except for the  pilot carriers needed to sync up the receiver 
demodulators--and that  carries no "intelligence."

RF 



*************************************
Very creative these engineers that come up with this stuff and squeeze it  
all into the same bandwidth....and what is more interesting is they did it using 
 those hot unruly unstable tubes.
 
Lets hear it for our enterprising engineers around the world.
 
Dave