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Old 7th Mar 2005, 12:55 pm   #51
oldeurope's Avatar
Join Date: Dec 2003
Location: Solingen, Germany
Posts: 727
Smile Re: Multi-Channel VHF Modulator Design

Hi David,
if you want to be as quick as my modulator in compensating
DC changes you must use a 2,5nF at pin 9.
And if you want a change in brightness over a line as low as in
my modulator you must take 47nF at pin 9.
This is the problem.
You will find no satisfieing compromise in your circuit.
The only way is to make a good DC restorer in front of pin 9.

In the old TV's they have a 0,1uF and 2M Ohms at the sync
seperator. You must make sure that this gets not in trouble.

Kind regards

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