Cool, thanks! I already ordered a new video cable. The one that plugs into the video port not the RF port.
And... I ordered a XM301 modem. I'm gonna try to get my 800XL back online! My Dad can't stop me now!!!!!
Yeah, is it the just composite video version, or the composite+ svideo (luma/chroma) version? Just remember that on the xl Atari neglected to connect the chroma pin inside the system.
Did you try your current RF setup with your neon signs off? I have a suspicion that they might be causing the interference you are seeing.