Best Electronics Atari 2600 Composite Hack

[stlouisrod]

So I installed the best electronics $20 composite video hack on my Atari heavy 6er, all soldering done with professional equipment, all pieces in the correct place per the 20+ page instruction manual. The RF signal before the replacement was well-saturated, and accurate, though it had noticeable streaking of color to the right of a graphic. There was also noticeable RF interference visible in games like Circus Atari, with that blue background.

 

RESULTS:

 

The composite video definitely has much less (practically no) signal interference common to the RF method, little to no color streaking, and a sharper more solid image with little to no dot crawl.

 

However, no matter how much I tweaked the hack's voltage pot, and the original CLR ADJ pot on the Atari PCB, I could not get perfect reds and greens on the color bar chart. The greens were a bit weak, and the reds too pink. The acid test is Barnstorming where you should have a bright yellow plane against a nice medium green background. Instead the plane almost disappears into the background since the yellow is too close to the green.

 

But the REAL annoyance is that in some games, a particular color combination of pixels results in a bizarre third color. For example, in Stampede, the bottom half of the red cattle (the legs) are literally YELLOW! And the deep red (brown?) cattle look nearly black. In Kaboom, all looks good until you look at the bomber's face. Instead of a smile, it looks like he's been punched in the face with a bunch of gray swiggles where his nose and mouth should be. His middle body also looks super thin, as though he lost 50lbs. And it's not just a high-res graphic mode issue. The cars in Indy 500 have a yellow double image surrounding them, which varies from barely visible to extremely annoying depending on the background color displayed.

 

QUESTIONS:

 

Has anyone else noticed these anomalies in a composite hack before, and if so, were you able to remedy it? Any idea where the issue is coming from (resistors, diode, transister, pot adjuster)? Would anyone in the community be interested in buying this heavy 6er from me for what I have into it ($180 for console and original Atari A/C gray power brick)? Cosmetically it's in great shape. I replaced the player 1 db9 port since pins were pushed inside it, and replaced 3 of the stickier switches with real Atari replacement switches (new old stock).

[SoundGammon]

I've seen where a site recommended removing the tall coil by the audio mixing to the video for cleaner video!

 

If you're not using the RF output it should be ok.

[stlouisrod]

I've seen where a site recommended removing the tall coil by the audio mixing to the video for cleaner video!

 

If you're not using the RF output it should be ok.

Interesting idea. Though I don't see how the image could get any "cleaner". It's simply palette-inaccurate and occasionally corrupts side-by-side pixels depending on color combinations. Maybe you can specify what you mean by "cleaner"?

[stlouisrod]

Some pics of the issues...

[Keatah]

Is that carpeting you have on the wall?

 

But the REAL annoyance is that in some games, a particular color combination of pixels results in a bizarre third color. For example, in Stampede, the bottom half of the red cattle (the legs) are literally YELLOW! And the deep red (brown?) cattle look nearly black. In Kaboom, all looks good until you look at the bomber's face. Instead of a smile, it looks like he's been punched in the face with a bunch of gray swiggles where his nose and mouth should be. His middle body also looks super thin, as though he lost 50lbs. And it's not just a high-res graphic mode issue. The cars in Indy 500 have a yellow double image surrounding them, which varies from barely visible to extremely annoying depending on the background color displayed.

 

I could see my younger self having nightmares about that. Stuck behind the TV set. MadBomber moving left and right. Ready to get me if I come out. Crawling out from under wouldn't work, I'd get bombed. I suppose i could jump over the TV set because he doesn't move vertically.