Circuits for removing retrace lines

[Steve McVoy]

Phil, the circuit on our site won't work with the Admiral, since the video is fed into the CRT grid and the pulse will be the wrong polarity.

The circuit posted by bigaudioal is a nice solution for sets like the Admiral. It should be noted that it can produce either a negative or positive going pulse, depending on which wires in and out of the transformer are used. You will have to experiment with this to produce the proper polarity pulse (negative going for a set that feeds video to the CRT grid).

[old_coot88]

Originally Posted by Steve McVoy

Phil, the circuit on our site won't work with the Admiral, since the video is fed into the CRT grid and the pulse will be the wrong polarity.

If a person wasn't averse to having a SS device in a vintage set, i wonder if a phase inverter such as this might be useful. The transistor would be an NPN video driver (high voltage) type, and the R and C values chosen as needed...

[old_coot88]

Originally Posted by old_coot88

If a person wasn't averse to having a SS device in a vintage set, i wonder if a phase inverter such as this might be useful. The transistor would be an NPN video driver (high voltage) type, and the R and C values chosen as needed...

Minor error on vert. out connection. Doh.