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Old 08-29-2024, 02:31 PM
ARC Tech-109 ARC Tech-109 is offline
Retired Batwings Tech
 
Join Date: Jun 2020
Location: Planet Earth
Posts: 611
LM1881 with an NPN based inverter feeding the horiz AFC. I'm not sure if something was missed in the string of posts but the circuit is only to work in place of the original sync separator not to generate sync. The one issue I'm dealing with is the capacative coupling of the "Phil Nelson design" video input interface amplifier posted on page one of the thread and the lack of both DC restoration and linearity needed for the Magnavox separator to work correctly. The LM1881 is fed right off the 12AT7 input amp and breaks down the vertical, horizontal and burst/back porch to their own outputs, there is a timing resistor/capacitor that is used to set the pulse widths and this has proven to be an asset with unstable sources like VHS tape that doesn't pass thru my TBC, it also stabilizes the vertical during DVD playback so it's not affected by the Macrovision garbage in the blanking bar.
I did post the schematics back a few, they're links to the outside host imgur.com as videokarma will not allow me to post anything large enough for the needed details, I will post more progress pics and screen shots once I find my USB cable.

Last edited by ARC Tech-109; 08-29-2024 at 02:54 PM. Reason: had nothing better to do over dinner
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