My Zenith Porthole Restoration Thread - Videokarma.org TV - Video

CoogarXR · #1 03-01-2011, 08:58 PM

Welp-

I picked up a Zenith Porthole TV over the weekend. In my "introduction" thread I mentioned how I came upon this TV.

Basically, I brought it home, set it in the garage, blew it out with my air compressor, and brought it in the house.

I still don't know what model it is, I haven't looked that close yet

. The previous owner told me that it doesn't work, and he never plugged it in. The owner before him told him it didn't work. Nobody really knows to what extent it "doesn't work". I only paid $40 for it, so no biggie if I can't get it working. I just know, after reading many posts on here, I'm not going to plug it in and "see what happens"!

I have a lot of modern electronics experience, but I have never worked on a tube set before. I look forward to you guys helping me out with this. I will probably start with a full recap before I try anything else.

Here's a pic of it. I will probably begin working on it this week or this weekend. Are there any quick tests for the CRT to be able to tell if it's any good before I go through the trouble of recapping?

Thanks fellas!

David Roper · #2 03-01-2011, 09:21 PM

I can honestly say I don't recall ever seeing a 12" 1951 porthole console before. Nice find!

Phil Nelson · #3 03-01-2011, 09:24 PM

Absent a CRT tester, about all you can do is check the CRT filament pins for continuity. A few ohms means the filament is intact, infinity means it's a dud. You can find tube data sheets here:

http://tubedata.tigahost.com/tubedata/

It might have an intact filament but still have weak emission, of course.

Phil Nelson
http://antiqueradio.org/index.html

bandersen · #4 03-01-2011, 09:25 PM

Quote:

Originally Posted by CoogarXR

...

Here's a pic of it. I will probably begin working on it this week or this weekend. Are there any quick tests for the CRT to be able to tell if it's any good before I go through the trouble of recapping?

Thanks fellas!

That's one nice looking set

If you have a multimeter, you can check for filament continuity on the CRT. Those will be the pins to either side of the socket key.

***Eric H*** · #5 03-01-2011, 09:50 PM

Nice set! I love Portholes.

That should be a 12UP4 tube, this is a metal/glass construction tube, they tend to be bad more often than all glass tubes because of leakage however the smaller ones seem to have a better track record than the larger sizes. (Search 19AP4)

You can check to see if it's still under vacuum by removing it from the set and looking for the Getter Flash on the neck of the tube, shiny and dark indicates it's under vacuum, white and powdery means it's gone to air.

I notice some discoloration on the screen in the upper right side, I'm presuming it's just dirt but I'd inspect it closely.

Handle the tube very carefully, be very careful not to bump it on the rim around the screen as that is it's weakest point for cracking.

Also note that when the set is operating the entire bell of the CRT has 10-12 thousand volts on it.

I'd also take a good look at the Flyback transformer, they are a known trouble spot on these Zeniths, just visually inspect it and see if it looks burnt.

CoogarXR · #6 03-01-2011, 09:51 PM

Quote:

Originally Posted by David Roper

I can honestly say I don't recall ever seeing a 12" 1951 porthole console before. Nice find!

How can you tell it's a 1951?

bgadow · #7 03-01-2011, 09:57 PM

What part of the country are you in? Maybe somebody on here is close enough to lend you a crt tester. If we can narrow down which model it is I might be able to dig out a Sams Photofact to send you.

CoogarXR · #8 03-01-2011, 09:59 PM

Quote:

Originally Posted by Eric H

I notice some discoloration on the screen in the upper right side, I'm presuming it's just dirt but I'd inspect it closely.

It only looks that way in the picture, in person the screen looks uniform. It must be a reflection or something...

CoogarXR · #9 03-01-2011, 10:00 PM

Quote:

Originally Posted by bgadow

What part of the country are you in? Maybe somebody on here is close enough to lend you a crt tester. If we can narrow down which model it is I might be able to dig out a Sams Photofact to send you.

I am in north-central Ohio.

Phil Nelson · #10 03-01-2011, 10:15 PM

Are you familiar with the ETF museum in Hilliard? (Just outside Columbus.)

http://www.earlytelevision.org/index.html

Phil Nelson

skillybob · #11 03-01-2011, 10:21 PM

Nice looking set. I would like to have one myself. Good luck!

sean · #12 03-02-2011, 07:48 AM

It is a 1951 model H2250R (chassis 22H20). The escutcheon is the giveaway on the model year. I used to have one and have a web page on the restoration of it: http://www.angelfire.com/electronic2...R/porthole.htm It originally had a 12UP4 CRT in it but mine had a 12LP4 in it. Zenith had a kit to convert the chassis from the metal cone tube to the glass tube. The factory service manual and Rider's service information are available on the ETF website: http://www.earlytelevision.org/tv_sc..._diagrams.html

ggregg · #13 03-02-2011, 08:01 AM

Here is my 16" 1951. As you can see, even though the tube is bigger, the escucheon design is the same.

CoogarXR · #14 03-02-2011, 04:34 PM

Sean- Awesome job on yours! Thanks for the links, I am sure that will help.

ggregg- Nice Porthole (sounds strange to say to another man, lol). Does yours work? One like yours came up on craigslist when I got home from buying mine. If I had space, I'd buy it too

Sandy G · #15 03-02-2011, 05:20 PM

There's a leather-covered 10-12" 1950 tabletop model porthole Zenith-I can't remember the model name-that has a video on Youtube of Liberace playing "Nola" that I've lusted over for years...The TV, NOT Liberace....(grin) Just somethin' about a Porthole, & the whole "1950" thing going on about it...But I guarantee you, put a well-restored Porthole alongside the latest whiz-bang HDTV widescreen video display unit-I shudder to call 'em TVs anymore-and see which one generates the more grins & comments.