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Old 08-01-2019, 01:24 PM
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Robert Grant Robert Grant is offline
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Join Date: Feb 2008
Location: Monroe County, MI
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Quote:
Originally Posted by old_tv_nut View Post
Analog NTSC co-channel stations were offset by 10 kHz, which turned the interference from a wavering picture into horizontal sine wave "venetian blinds."

At least one company sold a filter that plugged into the back of a monochrome TV CRT (and the socket then plugged into the filter), which contained 10 kHz traps for the grid and/or cathode leads.

I don't know the electrical details, but I have seen pictures of one. Thought I might have a picture, but can't find one.
To be effective, it would also need a 20kHz trap for when a plus offset and a minus offset station collide.
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