Muff's Modules & More

smrl · Posted: Sun Jul 01, 2012 6:46 am Post subject: add subcarrier sync to your CVE

Pretty simple. Just put your subcarrier at pin 3 of the AD724. I used a BNC jack with a grounding lug washer (not sure what you call it) and drilled it out to use as a bracket. Connected it to one of the screws that holds the two PCBs together. Certainly not the most durable... But I used a small length of BNC cable which I have strapped to the rack that the module's in to limit the amount of stress it gets.

The signal I used to synchronize was the 'subcarrier out' from a WJ-5600 SEG. This way I don't need the LZX to be the master sync source. This is a 2Vp-p signal w 75ohm impedance. The color was stable and it worked well but the phase was wrong. Still not quite certain why that would be, but I could well have had something else not quite configured right.

smrl · Posted: Sun Jul 01, 2012 6:53 am Post subject:

You still need to provide a video signal to the VSG from the same source to fully synchronize. This just makes the colors not strobe due to the freerunning subcarrier in the CVE.

lizlarsen · Posted: Sun Jul 01, 2012 2:30 pm Post subject:

Nice work!!

lizlarsen · Posted: Mon Jul 02, 2012 7:37 pm Post subject:

You know, if people wanted it, we could easily provide a companion module for the CVE that would upgrade the top board (the one with the actual encoder chip) and provide a breakout panel with BNC inputs. It could also be setup to distribute TTL level syncs to the LZX system. This configuration would require an external broadcast sync generator, but would replace the need for an LZX Video Sync Generator module (you would need the Triple Video Interface then, to replace the VSG's external input features.)

The upgrade board + breakout module would probably be something like an 8HP panel and would cost around the same as a Video Sync Generator I'm guessing.