wrote:

Hi all,

It's me again, attempting yet another mad science project, and I have
practically googled the subject to death before thinking of asking this
group for help:

I am wanting to put video (preferably color but will settle for
grayscale) onto a UHF TV channel for inhouse use only. I am
considering doing it as follows:

1) Convert output of a VGA card to composite video using resistive
combiner
(found a few on net).

2) Place composite video on VHF channel 3 using a game modulator.

3) Upconvert the video signal on VHF to UHF by with a local oscillator
whose frequence is the difference between the channels. I'd use an
active mixer circuit from the VHF/UHF part of the Handbook to do this.

4) To test functionality, attempt to tune in using either an analog TV
receiver or a TV tuner card.

Question is this:

Is point 3, upconverting video from VHF to UHF, a generally workable
technique?

Any other gotchas or pitfalls to my intended approach?

Thanks in advance,

The Eternal Squire


Motorola/Freescale has several ICs designed for video modulators that
use PLL tuning. One of them may do just what you want, rather than
building an upconverter.

http://www.elecdesign.com/Articles/I...ArticleID=4890

--
Former professional electron wrangler.

Michael A. Terrell
Central Florida