CompuServe Thread

Forum unknown · Videophile

#Genlock

3 messages in this thread
#69337From: gene lambertMay 25, 1987 6:25 PM
I just read Ralph Landry's resistor fix for the genlock and am not sure that the symptomns he described (tearing of the screen with no video present at the input) are the ones that are bothering me. I have observed with my genlock, and with a loaner from my dealer, distorted video levels (setup and white), and strange color burst which is offset around 20 IRE down toward sync. This results in some unacceptable video when output to tape, which is my primary usage for the genlock. I sent a message to CBM and they requested that I return my unit under a "priority return", but have not done that yet. If you could find the other files (Stan's), I would most appreciate it. The Amiga is so close to being useful in some video applications that it is a real shame to see the genlock ruin it, and I'm sure that there are others out there who have given up trying to make their units work. Thanks again for the effort. Gene
#69340From: joanne bandlowMay 25, 1987 6:49 PM
Howdy…. your message on Genlock rang a bell. We've seen EXACTLY the same distortions on the back porch of horizontal sync… mangled color burst with negative dc offset, and a strange H-sync waveform. We temporarily got around that problem at Viacom by running the output directly to a vtr, and playing it back thru a tbc. I also contacted Commodore, and they said (1) There's no fix for it, and (2) What do you expect for the price, etc…. I've been inside the unit and cannot find a tweak for the problem. The other fix you mentioned (resistor clip) is for those units that "jump" once in awhile when no input is present. We had that problem, did the fix, and voila, it works, with no side effects. Our first problem, however, is still there. The easiest way to fix it is with a downstream proc amp, which will strip off the original sy& blanking, and insert new sync, colorburst, etc. I've spoke to several other owners of GL, and all report the same thing, though one person said the burst had a POSITIVE 20ire offset instead of negative…. this leads one to believe that not all Genlocks are the same. Just when you thought it was safe to use it for production…….
#69340From: joanne bandlowMay 25, 1987 6:49 PM
Howdy…. your message on Genlock rang a bell. We've seen EXACTLY the same distortions on the back porch of horizontal sync… mangled color burst with negative dc offset, and a strange H-sync waveform. We temporarily got around that problem at Viacom by running the output directly to a vtr, and playing it back thru a tbc. I also contacted Commodore, and they said (1) There's no fix for it, and (2) What do you expect for the price, etc…. I've been inside the unit and cannot find a tweak for the problem. The other fix you mentioned (resistor clip) is for those units that "jump" once in awhile when no input is present. We had that problem, did the fix, and voila, it works, with no side effects. Our first problem, however, is still there. The easiest way to fix it is with a downstream proc amp, which will strip off the original sy& blanking, and insert new sync, colorburst, etc. I've spoke to several other owners of GL, and all report the same thing, though one person said the burst had a POSITIVE 20ire offset instead of negative…. this leads one to believe that not all Genlocks are the same. Just when you thought it was safe to use it for production…….