Need Help with CTC 16 Tuner

[southernguy]

I decited the other day that I was going to give my CTC 16 Chassis a good bath. It was nasty with a lot of dust, dirt, and more gewy dirt. While trying to be very carefull, I put the tuner in a trash bag and ziptied the tuner down so it would not get wet and be going everywhere. Got the chassis all clean like new. Anyway, when I started to put everything back together, I noticed that one of the wires going to the tuner had come off. There is a Red, White, and Brown wire going to the tuner. The brown wire is the one that became deattached from the pin on the tuner. I assume it is for the tuner lights. There were three wires soldered to that pin. From that pin on to the tuner lights. But, I can't tell if the pin is grounded to chassie of the tuner or not. At the top of the pin it looks to be separated from the ground. Ok, well the lights are grounded to the chassis/mask with a clip. I am getting a dead short on the tuner light socket. Oh NO CRAP, . Hmm, so then I compared to my CTC 31 Tuner. Got the same reading. So how do the lights work. Also tried another meter and got the same reading. Will the tuner work if I just disconect the brown wire? Also wondering if the brown wire was even connected in the first place, it was shorter than the other 2. The lights worked before.

[blue_lateral]

I think the pin is probably a feedthrough capacitor. Its a capcacitor to ground, but the pin goes through to the other side as a solid pin. From there I'll bet it feeds the tuner filaments. Does it still test shorted if you pull the tubes out of the tuner?

John

[southernguy]

Still reads a short when I pulled the tube. There is only one and its a 6KZ8

[blue_lateral]

Theres a second one. It's a "nuvistor" and its dead center in your first picture. Little guy. Probably a 6cw4 or 6ds4.

John

[southernguy]

Pulled the "nuvistor" and 6KZ8, still reads a short

[blue_lateral]

Oops. All the wires are still soldered on the pin, arent they? I didnt think of that. (even though your picture clearly shows it....D'OH!)

I'll still bet that pin is a feedthrough capacitor feeding 6.3 volts to the filaments. You are probably getting the short because all the filaments, and the 6.3 volt winding on the power transformer, are connected from there to ground. I'll bet its normal. I have a 16, but it isnt here. I'll see it tomorrow, though and i'll get a good look and probably get pics of how the wires are hooked up.

My guess is that the 3 brown wires do go together just like you thought. One wire is probably 6.3vac from the chassis, one for the pilot light, and one for the filament supply on the UHF tuner.

Good luck, I'll bet its fine.

John

[blue_lateral]

I had a look at my '16. Testing shorted is normal, as that is the main filament circuit. The hookup you have should work fine.

Mine is laid out a little different, the vhf and uhf tuners are side by side. The brown wire comes from the chassis and goes to that wafer switch on the back of the vhf tuner. From there another brown wire comes from the *same* terminal on the wafer switch up to the terminal on the vhf tuner that we have been talking about. another brown wire goes from the terminal to the pilot light.

The second terminal on the wafer switch feeds the uhf tuner and pilot light.

John

[southernguy]

Thanks John for the info, I will put this thing back together as soon as I can. Can't wait to get it to going again. The dust buildup was stinking up the house. Plus, theres nothing like a clean chassis, makes it easier to work on.