Zenith porthole questions - Videokarma.org TV - Video

josephdaniel · #1 05-16-2013, 10:27 AM

Just curious but how how well were those Zenith port hole sets made and what parts in them seemed to fail most oftin? (besides the metal CRT's in them) I have the chance to get one for a price I absolutly can't resist!

kramden66 · #2 05-16-2013, 11:13 AM

get it !!!! the worst that could happen is you have a display piece.

do you know a model number or chassis number or have a picture ?

i've worked on two but they were early versions , one wasn't much of a problem a 16" , the other table model had a replaced flyback , i hear this happens a lot and the flybacks aren't good or replaced , it is the 10" mayflower the first porthole if i'm not mistaken , only real issue i had with that one was the horizontal oscillator transformer had an open widing in it , so i had to replace it but couldn't locate a replacement , i then had to adapt a rca type transformer and mount it in the set , works but took a while to figure out.

mike

josephdaniel · #3 05-16-2013, 11:58 AM

Here is a picture

Electronic M · #4 05-16-2013, 01:09 PM

I've got a 16" model a bit newer than that which STILL works on the original caps (though 2-4 of the papers were replaced with maroon drops by some tech decades ago). If the Price is right go for it.

josephdaniel · #5 05-16-2013, 01:19 PM

WOW! Zenith must have had something added to their wax because to me it seems that there are more Zenith sets operating on original caps than anything else. I know it has a weak picture tube but not much else! I really hope I can get it sometime in the next few weeks.

Sandy G · #6 05-16-2013, 06:03 PM

I THINK I read this here-Commander Eugene F. McDonald, Jr., the head of Zenith, reportedly DIDN'T much like television-Mainly because his nemesis, Gen David Sarnoff, of RCA, had most of the patents. But McDonald also saw TV was gonna be too big of a market for Zenith to ignore. So he told his engineers to develop a TV-but NOT to bring it out til they got it RIGHT.. Maybe THAT would explain why now, even 60 yrs down the road, the Portholes are STILL giving good service to appreciative owners..

josephdaniel · #7 05-16-2013, 06:27 PM

Here are some better pictures.
It is a G2438RZ Lincoln model. It has a Brightener on the CRT and the pictures are after a "clean" and then a rejuvenate and the emissions are in the middle of bad and good

I think it would still produce a watchable picture in a dark room for testing until I could locate a valid sub or a replacement. My guess it that this set was retired due to the dim CRT. But the price is right and I think I am going to try and get it if I can find room!

*zenithfan1* · #8 05-16-2013, 08:03 PM

Try restoring the tube with a Sencore CR70, If you can borrow one or buy one. I did that for a member here and IIRC, the tube still shows a decent picture. Tom, Wasn't it your set I did that to?

Electronic M · #9 05-16-2013, 09:14 PM

Quote:

Originally Posted by zenithfan1

Try restoring the tube with a Sencore CR70, If you can borrow one or buy one. I did that for a member here and IIRC, the tube still shows a decent picture. Tom, Wasn't it your set I did that to?

I believe it was you and Nick who woke the CRT on my porthole. It was stone dead at the beginning but it eventually showed life. It is still weak without a brightener, but it is MUCH better than having a dud tube.

Here is a picture of it running two years back.

Haven't gotten around to running it since then. I haven't really done much with it since I'm on the fence about recapping it.
Most of my major projects have been on hold as I have so many little fix and sell/ fix to put away radios and such it has been hard to get bench space for the bigger stuff, but once that is done and I purge some things that are cluttering up my basement I can get to big stuff like my CTC4.

josephdaniel · #10 05-16-2013, 08:23 PM

That's not actually my picture :p it's the sellers who is a member here sent them to me.
What is the difference between a tester like that B&K and a Sencore CR70?

bgadow · #11 05-16-2013, 09:34 PM

I have a Mayflower and I can tell you that it had more bad resistors in it than anything else I've worked on. There is more to these sets than there needs to be. Well worth grabbing, regardless.

josephdaniel · #12 05-16-2013, 11:28 PM

Hope fully when I get the set I can get away with just replacing a few electrolytic caps on the powersupply chassis and if it dosent work identify the scetion having trouble and then just replace one paper cap and check. This is hopefully what I will do