Zenith H2447R 19" Porthole TV

[Crist Rigott]

Did some work around V9. Here are the before and after pictures.





And some around V14.





And an over all picture of my progress.

[Crist Rigott]

My high voltage wire came in so I finished the Flyback wiring. I decided to use some new 20Kv 22awg wire. I've used this stuff before and it has worked well for me. The working H.V. is about 12 to 14Kv.
I used some heat shrink to increase the diameter of the wire and to provide some extra abrasion resistance as it passes through the then guides. I then soldered it to the 1B3GT tube socket and used several layers of heat shrink tubing to provide some extra strain relief on the wires as they go into the tube socket. I then used some lacing cord to tie the wires together before they go into the tube socket shell.

I also used some of this wire for the plate cap wire for both 6BQ6GT and the 1B3GT tubes. I'll terminate the CRT HV lead during the dry fit phase.

[Crist Rigott]

OK guys, I have some questions for the disc capacitors in this TV. I know they should be good, but I tested one and it was 50% high. So I'm thinking that maybe I'll replace them. There are only 10 of them.
My question is what do I use to replace them? I know I need ceramic disc and I'm thinking of getting 1KV type. I know there are by-pass and coupling caps. Do I get COG, NPO, Z5U, Y5P, etc?
Below is a simple chart I made up that shows the SAMS parts list and the cross for each size cap. Also the Item Number of each cap. I checked the old Allied Catalog archive but they don't really list the specs for those caps.
Any help would be appreciated.

[Crist Rigott]

I have finished the main chassis except for the IF Strip.
We, the VRPS of Dallas, has our annual convention this weekend so there will be very little work and posting on my progress.

[EdKozk2]

I looked up your disc cap numbers in a 1953 jobbers catalog. Z5U and 5YP type caps will work fine. The originals were rated for 500 working volts DC or better. The tolerances were 20%. The .01 cap should be 600vdc or better according to one brand.
Ed

[Crist Rigott]

Great information. Thanks Ed.

[Kevin Kuehn]

On the electrolytic's heating concern: I tend to believe ambient heating from transformer and tubes is the dominant factor, but I suppose there could be a small accumulative effect. Many manufactures mounted cans under chassis with little concern for airflow. At any rate it would be interesting to check their temperatures relative to surrounding surfaces of the chassis.