What kind of wire to do A/V mod in the 7800?

[Dauber]

I got the 2600/7800 A/V mod kit from Vintage Gaming and More, followed the instructions to the letter, and...got no video signal. Audio works, but not video...and I really think the wire connecting the video is bad, especially as it broke off the motherboard three or four times, requiring a re-solder; the wire connecting the ground was also bad, as the thing broke into several pieces literally when I took it out of the bag, so I'm thinking maybe I'm not getting video because of bad cables; that would also explain why my sound (both POKEY and TIA) has a buzz...

 

So I'm thinking it might be just the wires. I live walking distance from a Radio Shack, so I can just run over there and grab some wire. But what do I ask for??

[PSW]

I've done this mod twice - once from scratch using directions posted in this forum and the second time using the mod board from vintage gaming and more. In the "from scratch" method I discovered that my channel select switch on the motherboard was cutting off my video. Once I flipped the switch to the right channel, SHAZAM!, I got my video back. In my second install with the premade board, I failed to remove the sound resistors according to the instructions and I could "see" my sound in the video. Certain sounds would cause a distortion in the video. Once I pulled the resistors, the problem went away, and my video was clear as a bell. I'm not sure if any of these apply, but I hope this helps you in some way.

 

Sorry, I failed to mention that I used solid hook up wire from Radio Shack for both installs, and I tinned the wire before install.

Edited January 6, 2013 by PSW

[Dauber]

I actually removed the channel selector completely.

[Dauber]

OK, just to update...I invested in a multimeter (an analog - go ahead and yell at me, I don't care!), and found that I wasn't getting a good connection across the ground wires. I completely replaced it, and...*poof!* Solved the problem!

 

Only thing now is that POKEY is barely audible. Not a huge deal because the only POKEY games I have are Beef Drop (which uses both POKEY and TIA) and Ball Blazer. I think I know what the problem is (I was impatient and used speaker wire and I think some of it frayed) but at least I have a playable 7800 again!

 

And the difference between using the old RF modulator and RCA cables is HUGE....the clarity is great!