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 Posted by R. Mark Clayton on 10/09/06 23:48 
"Radium" <glucegen1@excite.com> wrote in message  
news:1160431017.628911.56120@b28g2000cwb.googlegroups.com... 
> Hi: 
> 
> What is the color sub carrier frequency in SECAM video? 
> 
> http://www.high-techproductions.com/pal,ntsc.htm 
> 
Maybe (a) In SECAM, U and V signals are modulated using separate. color  
subcarriers at 4.25 MHz and 4.41 MHz respectively. (b) They are sent in  
alternate lines 
 
However as with PAL and NTSC these need not be the same in different places.  
Have go with Google to try and find out. 
 
> The above site shows the color sub carrier frequency for NTSC [3.579545 
> MHz] and PAL [4.433618 MHz]. 
> 
> Of the video frequencies described [horizontal frequency, vertical 
> frequency, color subcarrier frequency], the color subcarrier is the 
> highest? Why is this? 
 
This is because for all three systems color was added to existing black and  
white (which is / was the same the world over) on a sub carrier well clear  
of the existing picture signal and sound sub carrier.  If you use a set in  
the wrong colour standard you get a black and white picture. 
 
> How would the picture quality look like if the 
> color sub carrier frequency was only 1 hz? 
 
Terrible, the subcarrier signal would interfere with the main signal and  
vice versa. 
> 
> 
> Thanks, 
> 
> Radium 
>
 
  
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