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Old 11-28-2011, 12:23 AM
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cbenham cbenham is offline
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Quote:
Originally Posted by old_tv_nut View Post
Here's a 1956 Crosley ad touting their "Picture Pulse" feature. Sounds like DC restoration to me (or maybe it's only keyed AGC?). Anybody have a schematic to see if these sets had DC restoration?
I found a 21 inch Crosley set in SAMS 317-4 dated 05-1956. The video is DC coupled from the detector diode through the single 12BY7 video amp tube to the cathode of the CRT. I guess this eliminates the need for a DC Restorer.

The brightness control is in the CRT grid 1 circuit where vertical blanking is also inserted.

The set has keyed AGC using a 6AW8 with a local-distance switch.

Cliff
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