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Old 17th Apr 2018, 4:59 pm   #3
FERNSEH
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Join Date: Mar 2005
Location: Gateshead, Tyne and Wear, UK.
Posts: 7,444
Default Re: DC Restoration questions

A slightly more complex frame gated vision AGC system is employed in the Ultra VT9-17 of 1955.
The gate pulse is derived from the anode of the frame output valve.
APC gate amplifier V8B (20L1) receives positive going video from the demodulator.
The 1956 model V17-60 employs a simplified version of this circuit.
Instead of using an APC amplifier (V8B) negative going video from the anode of video amplifier goes direct to the sampling diodes.

DFWB.
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