'51 Zenith Porthole - Page 2 - Videokarma.org TV - Video

electronjohn · #16 02-01-2010, 05:02 PM

How about the foam insulation used on water pipes? It's gray, comes in a variety of sizes and is easy to work with. You know what I mean...about 3' long, slit down the side to allow fitting over pipes?

7"estatdef · #17 02-01-2010, 08:54 PM

I've got that same 1950 set in a blond cabinet. It too has a few cracks in the gasket.
Terry

Charlie · #18 02-02-2010, 07:30 AM

Wow... I've got all kinds of ideas to consider and try... thanks guys! I appreciate all the input!

Although it won't work, I like Jr's ironic thinking- use a gasket from a real porthole! Yes they do have gaskets, but they're just O-rings and not very thick. The glass, however, must be at least 3/4 inch thick... maybe even a hair more. I brought one of those old portholes home years ago... it was a gift for my brother-in-law who likes to make things out of neat stuff. That thing (with the brass frame around the glass) was HEAVY!!

John Marinello · #19 02-02-2010, 07:06 PM

The bezel was originally grounded to the chassis in one of two ways: hard wired, or a spring wire that contacts the chassis when installed. The spring wire will be secured at the channel escutcheon, or the hard wire from the volume escutcheon to the same point where the power supply is grounded.

Charlie · #20 02-03-2010, 08:06 AM

I will take a closer look next time I pull it out. Perhaps there's a spring in there and I simply didn't see it. Thanks, John.

cwmoser · #21 02-05-2010, 07:53 AM

Charlie, I've about completed a restoration of a 1950 model Zenith Porthole. The whole saga is documented on www.AntiqueRadios.com under the Television forum.

Your first post peaked my curiousity in regards to HV -- "After Dave's recent enlightenment, I'm reminded to pay close attention and be very careful." Could you enlighten me on this?

I never even gave it a thought of potential HV shock from the front bezel until I started reading your thread. After reading this, I did post a picture of a wire on the front bezel that I wondered about and your posting showed me what it was.

CW

Charlie · #22 02-05-2010, 08:52 AM

CW: Dave got

ZAPPED

recently while having his hand in the back of a set... sounds like it wasn't very pleasant.

Sometimes, we need little reminders to keep us in check when it comes to playing around or near high voltage. At Dave's expense, his recent experience was my little reminder. Oh yeah Dave, thanks for the reminder!

In addition, this Zenith has one of those metal/glass tubes that has the entire bell charged, so I have to keep in mind about being extra careful. I haven't worked with too many of these tubes. I could easily see someone (someone being myself) just reaching in there with the set running to grab something. because that's what that person is used to doing. As like most people, I really just don't like pain. Pain sucks.

DaveWM · #23 02-05-2010, 10:05 AM

STILL have some pain it my upper arm from that, I just hope it will eventually go away... Yea I have def new respect for HV, its one thing to hear you guys talk about it, but a whole nother level to exp 1st hand.

jeyurkon · #24 02-05-2010, 10:49 AM

Shocks like that can even break bones when the muscles contract. Though I doubt that TV HV supplies enough current.

John

cwmoser · #25 02-05-2010, 11:29 AM

Quote:

Originally Posted by DaveWM

STILL have some pain it my upper arm from that, I just hope it will eventually go away... Yea I have def new respect for HV, its one thing to hear you guys talk about it, but a whole nother level to exp 1st hand.

So far I have not been zapped by my Porthole TV, but I know its only a matter of time. Just the other day I did something really stupid. I have an AC line cord with aligator clips for test powering my chassis. Absent minded me the other day plugged the cord in the wall and I picked up the other ends without thinking. Instantly I came to my senses and dropped the ends and unplugged the AC end. Luckily I was not shocked - but like I said it was simply luck that I was not shocked. Its easy to get so involved and not think about safety first.

But, I have been shocked by the CRT anode back in the 1970's and my reflexes literally knocked me across the room and out of my chair. Luckily there were no long term affects, broken bones or lasting pain.

CW

Charlie · #26 02-07-2010, 10:18 PM

While tonight's game was playing, I decided to try a soft start of the Zenith. So far, I've done nothing to the chassis other than clean out the dirt and give it a visual inspection. Hooked up a couple of meters to monitor B+ and spent a couple of hours bringing up the juice. Kept feeling cans to see if any were getting warm, but they all stayed cool.

By the time I got up to 60 volts, I figured I'd start to hear a little crackling thru the speaker, but nothing. It seemed the audio output tube wasn't getting warm. By the time I got to 75 volts, I figured it had to be burned out. Popped in a new tube and then started getting audio from my Dish receiver!

Slowly kept raising it to full power with no problems or issues. The B+ voltages were all looking good. Let it run a little bit longer then shut it down.

Plugged in the horz output tubes, brought the juice back up, and got a picture! Actually, was a pretty good picture other than not being centered just right. Didn't really have to make any adjustments for a lock. After running it for a little while, the verticle did get a little sensitive during certain scenes.

The HV was a little low... paperwork is calling for 10KV and I was getting 7KV. Even so, the brightness was good. I will try a new rectifier and see how that does.

The photos I took aren't so great... this new camera I have does not do screen shots so well... I think it has to do with the automatic setting and my flourescent overhead lights. I miss my old camera. So, it really looks better in person than these photos show.

All in all, I was very pleased to find things in working order with no smoke, fire, or sudden surprises. Considering it's nearly 60 years old, filled with black beauties, and has the original cans, I'm surprised it plays as well as it does. I'm sure once I get the set recapped, it can only get better.

bandersen · #27 02-07-2010, 10:34 PM

Excellent!
I used to be really paranoid about power up sets before doing a full recap. Lately though if the set looks OK visually I've been doing more slow start-ups just like you describe with some good results.

Charlie · #28 02-07-2010, 10:43 PM

I've had a time or two in which something blew. I had a BB cap in an RCA b&w set that blew the casing all the way across the room! Soft started an CTC11 that did fine the first few times, but by the time I turned it on for the fourth time, something in there got really tired and decided it was time to go. Sometimes I think we just get lucky. If a cap blowing is the worst that happens, I guess it's not all that bad.

Sandy G · #29 02-08-2010, 05:27 AM

Damnation, you boys are makin' me Lust Mightily for a Porthole !! The one I'd give Eyeteeth for is a "Claridge", the leather-covered tabletop model. There's one on YouTube, showing Liberace playing "Nola"...Me likey, me wantee REAL bad....(grin)

wa2ise · #30 02-08-2010, 03:05 PM

Quote:

Originally Posted by bandersen

... Lately though if the set looks OK visually I've been doing more slow start-ups ...

I'll do that to see if the unobtanium parts are good (flyback, CRT, power transformer and such). If I get some activity on the CRT screen, then I can proceed with a recap with confidence that I won't be wasting my time and caps.