With this post I ask for help from the fellow engineers on the board. :pray:
So I built two video encoder circuits for my homemade supergun.
On the first one I used the CXA1645 because it was simpler to built around it. I didn't like how it looked on my TV set because the chroma burst circuit would inject an "wavy dot crawl" effect on the image that would "piss the hell out of me".
Then I sucked it up and went on to build an much more complex circuit using an CXA1145 in hopes it would improve my image quality with CVBS and S-Video (yeah I know what RGB is, but it's not an viable option where I live :rolleyes:)
The second circuit alleviated the issue in a good deal (by having an better quality waveform for the CHROMA carrier) but I'm still NOT satisfied.
Feeding either encoder chips with square wave CHROMA carrier makes the image look like the Mega Drive video output... lol (Fixed saw-like effect on the edges of the image)
The supergun itself (with the CXA1645 encoder):
(This pic is a repost)
The image looks like this on a real USA TV:
The dot crawl artifact is particularly visible on the "h" letter of the game logo. :DOH: It will either roll to the left or to the right. Doesn't matter if it's CVBS or SVIDEO and I know it has to do with the phase of the CHROMA carrier clock input on the CXA chip. If I take the CHROMA burst out, the image is as SHARP as if it were tied straight to the tube (RGB) but B&W (d'oh).
Now here's the question:
I know that SONY solved this problem on the PlayStation console by using an triangular wave output of 3.579545Mhz as color carrier.
How I can possibly replicate that waveform in my circuit to get rid of that "wavy" dot crawl effect on my image ?