Modifying a B&W TV for composite video input

From: Gary Dean Hildebrand <ghldbrd_at_ccp.com>
Date: Mon Jun 30 23:48:00 2003

Ian Primus writes:

> I have read a lot about the SWTPC TV Typewriter, and I am interested in
> how people modified a black and white TV for a video monitor. I have an
> old black and white set that I thought would be fun to modify for use as a
> video monitor. Now, granted, I don't really need another composite
> monitor, I have plenty of old Apple monitors that will do the same thing,
> I just thought it would be fun, since it would be a challenge to find
> where to input the signal and how to do it. I found the PDF of part of the
> SWTPC TV Typewriter manual on a web site, and it explains the process,
> although not in great detail, and references a circuit diagram of what
> needed to be added, but the diagram is nowhere to be found. Does anyone
> have any instructions or hints that they may be able to give me? Has
> anyone done this before? Any advice would be appreciated.
>
> Ian Primus
> ian_primus_at_yahoo.com

First you have to deterimine that the set isn't hot chassis, and has a
transformer operated power supply. Then get a Sams's Photofact, so you can
find where the video detector diode is.

Somewhere in there is a point where you can inject baseband video. Not
knowing the schematic, your guess is as good as mine. If you know basic
electronics, you can look for a point where the scope video is the right
polarity, and about 1v p-p and inject it there.

Gary Hildebrand
St. Joseph, MO
Received on Mon Jun 30 2003 - 23:48:00 BST