Composite video signal in frequency domain..

Thread Starter

Himanshoo

Joined Apr 3, 2015
260
Can some one provide me a diagram of composite video signal as shown below in frequency domain (i.e Amplitude vs frequency curve )..?
I've googled it and found no luck yet...

Thanks in advance!!

comp.PNG
 

bertus

Joined Apr 5, 2008
20,104
Hello,

You will likely not find a frequency domain spectrum, as it will be rather random, dependend on the shown image.
There will be some signals stable like the sync signals and the color carrier signal and sound carrier.
The frequencies of these depend on the used system.
This page will give you an overview of most used systems:
http://www.stjarnhimlen.se/tv/tv.html

More info can be found in the links of this EDUCYPEDIA page:
http://educypedia.karadimov.info/electronics/television.htm

Bertus
 

Sensacell

Joined Jun 19, 2012
2,452
It's a nasty mess- with big spurs at the vertical (60 hz) and horizontal frequencies (15 Khz) and an undefined mess that depends on the image itself.

That's probably why you cannot find it.
 

Thread Starter

Himanshoo

Joined Apr 3, 2015
260
@Mr Chips ...could you tell me what will be the amplitude of the resultant amplitude modulated video signal for VHF band...as the amplitude of cvs is 1 Vpp ??

and would it be possible to design this signal for simulation for an rf tuner circuit (in link below) using LTspiceXVII...??

Screen Shot 2017-07-12 at 10.14.59 pm.png
 
Last edited:

nsaspook

Joined Aug 27, 2009
6,502
http://www.keysight.com/upload/cmc_upload/All/E206CATVTEC1.pdf?&cc=US&lc=eng
page 2-6
Now let's consider the various forms of signal level measurements in CATV systems. In Figure 1.3 typical dBmV levels are shown at various points throughout distribution lines. These levels represent the TV video carrier peak signal. The peak of the video carrier is simply the unmodulated carrier voltage, as shown in Figure 2.3. The peak detection value in Figure 2.3 (c) is the only meaningful signal level measurement because it is the maximum of the carrier signal as if it were unmodulated. Each visual carrier at the subscriber's drop must be at a specified power minimum level and within a given number of dB from each other. (Chapter 4 deals with these specifications in detail).
 
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