30 Jun
2003
30 Jun
'03
4:48 p.m.
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(a)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