UAV mod on 6 Switch colors are off

[+-^CrossBow^-]

1 hour ago, BriGuy_the_AtariGuy said:

Well, I removed the IAB and ran a line directly from the unused via next to C210 to audio out and am using the same ground as the video (composite install).  Unfortunately, I'm getting the same result, might even be a little worse.

 

I found a modding thread for stereo sound that takes audio directly off of the TIA pins 12 and 13, listed here:

https://forums.atariage.com/topic/199461-atari-2600-stereo-mod/

 

I'm almost tempted to do this, but bringing the right and left back together before outputting to the TV.

 

Have you done this before?  I'm just so confused because everything works great on RF. 

I'm personally not a fan of the stereo mod since the sounds are hard panned to the left or right without any mixing between them. Sounds also don't follow the action happening on the screen. 

 

What is interesting in watching that video is that the pattern only happens on certain frequencies it seems. Do you have the 2600 connected through that VCR? Or is that VCR built into the TV? I would try a different TV just to rule that out.

[BriGuy_the_AtariGuy]

The Atari is connected to the VCR, which is connected to the TV. I have 11 other consoles connected in the same way (one is a modded Colecovision) without any issues.

Before the UAV I tried the simple 2 resistor/1 transistor mod and got interference in the same spot, although it showed at pretty much every frequency. Can't help thinking that there's something else going on.  Here's the original mod:

 

I'll try a different tv and see where that gets me.

 

[+-^CrossBow^-]

The only option I can think of to try off hand then, would be to try a different TIA since the graphics and audio all come from that chip and is really the only other place I can see it happening from. RF might be filtering it out in some way but if you tried two different AV mods and get this on both, it is most likely the Atari itself as the issue and I would start with the TIA.

 

[BriGuy_the_AtariGuy]

😔

I was fearing that might be the case.  I'll do my due diligence and try a different tv, but if that isnt it... ill just have to revert to RF.  I dont have another TIA to swap in, unfortunately. 

[shear_xear]

I might have a spare TIA if you’re interested.  

[BriGuy_the_AtariGuy]

Possibly... tried it out on a newer TV (native composite inputs) and the interference went away!  I had some odd horizontal bars, but those went away after a minute or so.  I assume something warmed up.  Does this mean the TIA is good and it's time to get rid of my 35 year old tv? 😭