1964 Zenith 5111 comes to life!

[Phil Nelson]

Originally Posted by ctc17

Not to start a war here.....the mid 60s tvs on are not like the old bw stuff. The electrolytics rarely go bad. Zenith used some superior quality parts.

I've found bad electrolytics in newer gear than that, but haven't worked on any 1960s Zenith sets, so I'll take your word that their parts are that good. Maybe I need to switch brands

I used to think that the brown/maroon "orange drop" types were pretty good, but not so much any more. This week I went back through an RCA CTC-11 that I restored a couple of years ago and replaced about ten of them. They had seemed fine at the time, but didn't hold up -- creating problems with vertical linearity and horizontal stability. Nothing is forever, I suppose.

Phil Nelson

[DaveWM]

Same here on zenith filter caps, more likely than not they are fine. I have worked on several zeniths from the early to late 1960's so far only one was a problem and it was open (the pincushion correction on a 23x). Not only have the cans been ok, but to my surprize even the singles have tested well. I use my cap tester on them to test at rated voltage for open and leakage, so far they test every bit as well as new caps! So I have revised my thinking these days to check them, if they test like new I leave them be. I do like to add fuses to the B+ and HOT, the B+ fuse will cover the PT and the HOT will cover the fly if the horz osc decides to stop. The HOT fuse is a little tricky, CTC-17 has done some testing and a reg fuse does not seem to work properlyt here, a chem fuse would be the way to go.

Prob the best advise would be to check the HOT current and work on it if too high. Also you can prolong the sets life by reducing the line voltage, this will take a large load off. the set should work fine at 110vac, around here its often at 125vac. I have not done it yet but a adj to the HOT screen value would prob be the best way to address the higher line voltage put out today


I would recommend ALWAYs changing the coupling cap to the HOT, esp if its a brown/maroon drop. Also the 1kv hard covered (white tube) foil caps that are generally found in the vertitcal circuit. Those seem to be bad about 50% ot the time (leaky) you will know if the picture seems to be jumpy vertically.

[ctc17]

Originally Posted by Phil Nelson

I've found bad electrolytics in newer gear than that, but haven't worked on any 1960s Zenith sets, so I'll take your word that their parts are that good. Maybe I need to switch brands

I used to think that the brown/maroon "orange drop" types were pretty good, but not so much any more. This week I went back through an RCA CTC-11 that I restored a couple of years ago and replaced about ten of them. They had seemed fine at the time, but didn't hold up -- creating problems with vertical linearity and horizontal stability. Nothing is forever, I suppose.

Phil Nelson

Tell me about these.....I had a ctc35 I fought with for weeks on a vertical problem and it turned out to be one of these. They get lossy, change value when dc voltage is applied and drastically change value with temperature. I have had to replace more orange drops than electrolytics in 60s stuff.

Even though I hate to do it and admit it, the time is here when all the orange drop style need to be changed.

[DaveWM]

a old school cap tester is a good piece of gear to have, both for checking eletros and lossy film types. The dipped types (brown orange maroon) often test fine for leakage, but not so for values. They show up on the tester as a eye that does not fully open or has fuzzy edges. Heat seems to have big effect as well when they are bad.

I also check anything going in as a replacement. I have caught at least once my self installing the wrong value. Goes like this, I lift a leg test it, dial in the correct value, eye does not open up as it should. Remove the old part, get ready to install the new one, but put on the tester, hmmm thats odd its not opening at all. Ah Ha, I have a .01 not a .001, by leaving the tester dial in the orig position used to test the old cap it caught me try to replace it with a cap off by a factor of 10.

other cap tester oddness, disconnect any RF leads, I had a DVD player hooked up to a set, and turned on. Set is off and unpluged, lift one leg to test test bad (fuzzy eye on value test) take out of circuit test again, test fine. hmmm put back in, fuzzy eye, disconnect the DVD, and all is well.

make sure cap tester case is isolated from the metal chassis of the set, did not do that once and a cap kept testing as leaky. Not sure why but the cap tester was in contact with the TV chassis. moved it and everything tested normal.



stuff happens....