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Old 07-18-2015, 06:44 PM
Pete Deksnis's Avatar
Pete Deksnis Pete Deksnis is offline
15GP22 demo @ ETF 2007
 
Join Date: Jan 2005
Location: Big Rapids, MI
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Quote:
Originally Posted by old_tv_nut View Post
I have to comment that I can't think of a good reason to include 4.5 MHz traps in a video input circuit, unless the input was from a separate RF receiver. Why would anyone deliberately limit the bandwidth?

Edit: I can think of one reason - to create the same awful chroma delay and quadrature distortion that an IF amplifier produces, so that it matches the delay lines in the TV chassis.
Wayne, I figured it was their cheap and dirty way of matching the 20-dB down slope of the CTC4 i.f. (I've never worked on a CTC4 and only am going by how I interpret what the 1956 article mentioned about the i.f. response.)

Pete
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