Problem with CXA1645P

[skips]

I've been experiencing an odd issue with any third party CXA1645P encoders and just cant seem to figure out how to fix it. For some reason colors seem to pulse or ripple slightly. This gives things a crawling look when the screens start moving. The problem is not dot crawl, I do know that for sure. This looks much different from that issue. I have tried at least 3 different encoders on a Sega genesis, RGB NES, and a CMVS. All of them had the issue. Two of them were ones I purchase from

http://www.ebay.com/itm/220738410906?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

and

http://www.arcademonitor.com/converter_boards/rgb-to-ntsc.php

I even tried making my own and it worked but also suffered from the same problem. Even my older Sony Playstation (the bulky gray one) seem to suffer lightly from this problem (it uses the CXA1645M I believe). I think it might have to do with how the color is being generated. If you disconnect the oscillator on all of these encoders the picture does not ripple when its just black and white. I think it might be the TV not liking something with this specific encoder however my Sega Saturn does not show this issue and I am pretty sure it uses a CXA1645 as well. This problem has me stumped.


*Update* I tried it on another TV (20 inch Samsung CRT) and it had the same problem. I am stumped on this. Its only CXA1645 based encoders doing it.

[viletim]

It's caused by the asynchronous colour sub-carrier oscillator. Looks pretty bad doesn't it?

Usually everything related to video is synchronous inside a game console. To make your external encoder generate a respectable video signal you need to either feed it with a sub-carrier signal from the console (you'll have to go inside to get it) or phase lock your local sub-carrier to the sync signal (given that it's derived from the same clock source as everything else and is always present). I remember there was a PLL chip from Intersil/Elantec that was made specially for this task.

[skips]

I actually ended up getting a 36 inch sony triniton and it seems just fine with these encoders. I guess the other tvs just didnt like how they generated colors.