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  #46  
Old 02-26-2011, 10:15 PM
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Eric H Please don't scrap your Zenith, someone will eventually come along and get it running for you or buy it.

I'd love to have a look at it but I'm too far away!
Agreed! That sounds like a rare and nice zenith. If I was on the east coast I'd be willing to take it off of your hands. If you take it to the ETF convention in Ohio I'm sure someone(possibly me) will be more than happy to buy it.


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Tubejunke
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Originally Posted by Electronic M
In my bassackwards mind something has to work before it qualifies to sit on a shelf and go unused for months!

That is exactly the way I am! I (along with most of the women I have dated) have often wondered if it was some kind of mental condition that caused a person to have a drive to repair something just so it can sit on a shelf and get used once or twice a year in order to keep the capacitors in working order. Also, if I get stumped on something I seem to not want it around and the way things are now I am forced to go back in time and scrap it. I used to at least be able to give a TV set to someone, or better yet make a few bucks to make back some of the cost of replacement parts and the value of tubes. After NOT being able to find a loving home for my 1958 24" Zenith Space Command console set, neither for money or for FREE, I am just going to scrap anything that is not simply extremely rare. I had high hopes for the Zenith due to what seems to be a VERY low use chassis and crt and the fact that the 24" tube is not exactly common, nor was remote control at the time.
For me the reason I repair is for the challenge, and that high I get after finding and correcting a really tough bug. that and seeing somethimg over twice as old as me working like new, other things like braging that nearly every thing I own works etc. come second. There are exceptions to the if I can't fix it it gets sold or donated to the local radio club rule. I'll hang on to anything that I like the look of (especially art deco) also coveted sets like any color set that may have originally used a NTSC standard phosphor tube, any TV pre-1950, anything with a remote, any radio with a tube count of 14 or higher and anything that I want to have in my colection that I don't think I'll find again. Case in point I'm using a Philco beam of light (which is out of wack except for the amp) as the head board of my bed. I also have a policy of not parting out anything pre-1970, however I once made one nice radiola model fourty-something out of two messed up ones(forgive me father for I have sinned).

Please do not scrap that Zenith!

Tom C.
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  #47  
Old 02-26-2011, 11:41 PM
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Originally Posted by Electronic M View Post
Agreed! That sounds like a rare and nice zenith. If I was on the east coast I'd be willing to take it off of your hands. If you take it to the ETF convention in Ohio I'm sure someone(possibly me) will be more than happy to buy it.Please do not scrap that Zenith!
I really think that I could get it going myself as it is already recapped, but the problem lies deeper than that. I have posted on this before so I sort of hate to go off topic, but anyway the biggest hindrance of repair of this set is simply not having a way to power the chassis to do voltage checks and if I had a scope I would look at waveforms. The big 24" tube does not come out with the chassis, nor does the tuner, so I would either have to build a jig to hold the crt, or make necessary extension leads for the yoke and second anode HV connection; I could just unbolt the tuner and motor. The easiest and best approach would be to get lucky and find one of those small test crts to power the chassis. Anyway, I just didn't have the heart, or lack thereof to bust up the Zenith. With no interest in the set I have made further attempts at finding the problem. I used a megger to check out the vertical output transformer and the choke (while I was already close by) for grounded or open windings. I did a little probing around with a Huntron Solid State Tracker, but that is best used to compare footprints with that of a known good component in a similar or identical circuit. Really, it all boils down to good old signal tracing I think. I may just bite the bullet and build a wooden jig for that crt and get the job done. A low use, big screen 50s set with remote control would be a GREAT daily user I think. Oh, the remote is missing, but I think that they are pretty easy to find.

Thanks for the encouragement!
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  #48  
Old 02-28-2011, 11:04 PM
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I did some probing and found the 410V derived from the 420V boost was only around 350V. I measure R78 and it was high - about 8K.
I replaced that and got full height even though the 410V line was still low at 380V with 8V P-P of ripple.

Unfortunately, while I was adjusting various controls the picture starting breaking up. Then I completely lost the video and sound. I still have a good raster and all the controls respond.

I've already checked the tubes and replaced a weak 3CB6. The 5J6 is a little weak too, but I couldn't find a replacement so I tried a 6J6. That didn't make any difference.

I'll fire up my 1077B and try injecting signals at various points in the RF/IF stages. I hope it's something simple.



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  #49  
Old 03-01-2011, 01:13 PM
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I fixed the set (again)
It took a while, but eventually I found this bad resistor hiding under a coil


That supplied +130V to the 2nd IF stage. That's right before the detector so no picture or sound. I replaced it and got the picture back but no sound.

More troubleshooting revealed the coupling cap between the volume control and audio output tube had a broken lead. I quickly soldered that back on sound was restored


Better yet, I have full vertical although the control is near the edge of it's range. I'd still like to find out why the 410 line is a little low
When I first popped this set open, I found a 1.8K resistor someone had added between the 410 line and 10uF filter cap.
That seemed odd and I removed it. It might be worthwhile to put it back. Doesn't seem like adding a resistor is going to increase the voltage though.


Also, replacing the weak 3CB6 increase the gain and I have a brighter picture.
Odd that it and the 5J6 test weak now when they were good a couple weeks ago.
Maybe running this set for a few hours drained what life they had left ?

The picture is off-center to the left a little, but I can take care of that by adjusting the ion trap magnet or centering magnets.
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Last edited by bandersen; 03-01-2011 at 04:10 PM. Reason: corrected typos
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  #50  
Old 03-03-2011, 12:02 AM
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I put the set back together and it's playing well.
Sometime later this spring or summer I plan on repainting the cabinet.
I think I'll try using electrolysis to remove the rust and hopefully the paint too.

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  #51  
Old 03-04-2011, 07:03 PM
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Tubejunkie since you did not want to go off topic I sent you a PM with some suggestions.

Tom C.
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  #52  
Old 03-04-2011, 09:43 PM
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I masked off some of the orange on my paint test subject and put on a few coats of "Ivory Bisque" followed by a clear coat of the engine enamel. I think it looks great and is very tough
I examined the cabinet and it appears they also painted the whole cabinet orange first, than applied the white. Odd - I would have done it the other way round

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  #53  
Old 03-16-2011, 12:06 AM
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Here's one for sale in very, very nice condition! http://cgi.ebay.com/Vintage-1957-2-T...-/290541493996 (no affil.)

Is this plaid cover original ? It sure looks like it.
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  #54  
Old 03-16-2011, 04:29 AM
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That is an original cover, I've seen ads with those in them.

I Picked up some aftermarket plastic covers on eBay in Red and Pink for my Hotpoint/GE 9" and 14" sets.

They were NOS with the boxes but they had shrunk somewhat and it was a bit difficult to get them on the TV's

The Emerson 1232 8" Portable also had a zippered carrying case, I have one but it's falling apart at the seams and is stiff with age.
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  #55  
Old 03-16-2011, 02:51 PM
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maybe they used those covers as a work-around for the hot chassis issues those sets had.
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  #56  
Old 03-17-2011, 06:36 AM
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Green T-103

I have just had a mint condition T-103 as a gift: as all tv has switched to digital, few enthusiast want to mess up with VHF modulators.
I think it's a very rare set to find in Italy: actually I've been told that it belonged to a wealthy US family living in Milan.
In 1956 few people owned a TV, (they costed like 5-6 month wages) and no one was already caring for a kitchen - or holiday house - set.
The body is near perfect, inside is very clean. I've been told that it works, but I want to check it for leakages first, using a variac and isolation transformer.
Export sets like this have an additional auto-transformer to adapt to different line voltages, 220 included. And of course they are tuned to the 625 lines - 5.5 MHz intercarrier used here.
I have a schematic but not the SAM's service manual ...
Thanks for all the advice on this thread, I hope to begin working on it soon !
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  #57  
Old 03-17-2011, 10:56 AM
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I scanned the Sams for the 14YP3 chassis and you can download a copy here

It may be of some use to you. Good luck.
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  #58  
Old 03-19-2011, 03:59 PM
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A good source for dropping capacitors is old ceiling fans, you'll find them in the switch housing.
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  #59  
Old 03-20-2011, 12:33 PM
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The green T-103 I'm working on, as I said, was sold in Italy. It differs from the US market models in the power supply (see schematics). It's got an autotransformer. This increases the weight, but has a great bonus: it gets rid of the 20W resistor with an 85V tap for the heaters !
Additionally, it provides 220V for the B+, so that a voltage doubler circuit is not necessary, and the 2 selenium units are wired together.
I'm slowly conditioning the capacitors with a Variac now ...
Attached Files
File Type: pdf Admiral T-103.pdf (344.4 KB, 15 views)
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  #60  
Old 04-05-2011, 12:50 AM
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We've finally climbed out of the 30s so it's time to repaint this cabinet

I picked up a tub big enough to submerge the cabinet. I filled it with some water and Washing Soda (Sodium Carbonate).
I used a 2A/10A battery charger for the juice and a big old cold chisel for the sacrificial iron.


I was really surprised that the paint was bubbling off in only 30 minutes!
A few hours later and it was all off


It worked even better on the orange paint.


I had some gray and maroon primer on hand and used appropriately.


Now it's time to pull the chassis and dunk the rest of the cabinet.
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Last edited by bandersen; 04-05-2011 at 02:12 AM.
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