I need to put some digital iinfo, from a fast uart, possibly,maybe biohase mark, into a few lines of video blanking, on a standard 75R coax. 2 or 3 bytes per line will be ok
I was thinking of just using a simple PNP current source, from a
I'll have an Elantec sync stripper doing a lot of the hard work/ timing, somewhere in the system.
Any gotchas on feeding a coax this way?
Martin
None other than possibly the transmitter and/or receiver may not like the DC component, or the DC is blocked and the threshold shifts.
Surely there's some kind of buffer driving the cable? It'd probably be better to insert the encoding there.
...Jim Thompson
Look at how broadcast stations insert the time of day information into the video.
Tam
I agree, it would be so easy to add the signal to the video buffer, but it's basically an add on, to add telemetry, by using a bnc T piece to insert the signal as a switched constant current, and my Tek/grass valley manuals are long lost
Martin
No, that method was used in a lot of the cheaper analog broadcast equipment. There's a lot of good stuff about video here:
You can download past editions free, but unfortunately there's no article index on the website. There might be one on the DVD.
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