Hi guys,

I notice there are two Portholes on eBay, which I'm guessing is rare. Out of curiosity, what are these sets like to work on? And how do they perform in terms of reliability? I'd love to have one, as they're a real show stopper. But I have to think about getting spare parts if something unique like a flyback fails, unless it can be rewound. Difficult enough to source in the US, probably impossible for me in AUS. You read about how some brands/models have their various issues, and I wonder what stories are out there regarding these TVs. Also of course the CRT. Do any of the Portholes use metal CRTs? I've heard that they can lose vacuum eventually at the metal/glass seal. All info appreciated.

Cheers,

Adam

They are not as plentiful as Predictas, but they do seem to be among the more common vintage TVs. Perhaps people kept them around because of the different look, or because they were expensive. When Grandpa spent a lot on something, whether or not it was any good, people tended to keep it.

<begin rant>

This is 100% hearsay, since I have never owned one, but what I have read over the years about other people's experiences in restoring Zenith portholes has made me lose interest in buying one.

They seem to be prone to eating flybacks. Some use a metal CRT, with the attendant concerns about shock hazard and premature failure. Although they do seem to work after careful restoration, I don't recall anyone crowing about the wonderful build quality, or the performance, for that matter..

The porthole screen makes a distinctive look, but I consider it a marketing gimmick. Owing to the rectangular nature of a TV image, you have to choose between showing the full image with lots of blank space on the edges of the circle, or blowing up the image to fill the entire circular screen and losing a lot of picture information on the corners. Neither of those choices appeals to me. Most manufacturers simply used a mask to let you watch the complete image without staring at the dumb unlit edges of the round CRT.

<end of rant>

So, that's my anti-Zenith porthole rant. If someone left a free one on my porch, I might take it, but I have passed up opportunities to buy them and will continue to do so. I know there are people out there who have restored Zenith portholes and are glad they did so. Perhaps one of them will chime in to explain why I'm just being crotchety.

If you feel that you must have one porthole, there are more interesting choices out there, such as a Stromberg-Carlson TC-10. Here's a nice example:

http://www.myvintagetv.com/tc10.htm

Raytheon also made some cute porthole tabletops:

http://www.tvhistory.tv/1946-49-RAYTHEON-BELMONT.htm

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

Agree with the above and would like to add that all the 16" and 19" models use metal CRTs. Many of the 12" as well, but some are all glass. Also, many of the 16" models use the very hard to find 16EP4 rather than the more common 16GP4.

Everything Phil said is true, as far as I know. But, as the proud daddy of a 12" Zenith tabletop Porthole, I can only say that the utter sense of "Awe" & "Wow !" that people get when I show it off to them more than makes up for any bad traits it has. It is from a time that even HAVING a TV made you Something Special, & the Zenith's cosmetic design echoes that. It LOOKS impressive, even today, even turned off. "I'm a Magic Box, Look at me CAREFULLY !" it seems to be saying to the jaded denizens of HDTV 2014. Sure, a jellybean $10 set from 10-15 years ago might have a better picture, & shows more of said picture, but that's not the point. A Porthole IS a "Porthole" on a distant past, a time from before most of us were born, a time we usually only get to visit in history books.

I grabbed a 12 inch all glass CRT porthole, "Graemere" model, from Bob Anderson a while back. It's a single chassis, console model - think it's the 12LP4 CRT. I am NOT looking forward to trying to restore it, but it is one AWESOME looking set. Right now it is sitting patiently for me to acquire more experience and confidence in restoration before I tackle it. I did locate a NOS Merit flyback for it and have that tucked away too - just in case.

Worst part about this set is I cannot find a SAMS that has those great reference photos of the chassis in it. It is Zenith model G2346R, chassis 23G22. The only SAMS I can find for it (98-17) seems to show a totally different schematic with dual chassis and a 16 inch CRT. Even though my model and chassis number are listed on the SAMS it is not even close to my set.

I luckily do have the Zenith Service Manual for MY set, which at minimum just has the schematic. So I may have to work on this set with no reference photos that match my chassis, which will be tough for a guy with only a few years experience by the time I get around to this set. :(

I've restored just one Zenith Porthole and it was a 10" Mayflower model and it had a bad Flyback. At least it uses a glass CRT.

There may be nightmare restoration cases, but there are also ones that refuse to die.

I got one at the ETF some years back for 20$ that was beat to heck, had to have it's CRT rejuvenated back from the dead, and a new audio output tube popped in to replace the missing one. After that, with all original parts except for around 5 of it's original paper caps replaced with maroon drops from a ~60's repair and several tubes that had been replaced way back, I brought it up on a variac. Once I got the voltage up high enough I was greeted with this....
http://i1095.photobucket.com/albums/i469/ElectronicMemory/DSCN0664.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/DSCN0664.jpg.html)
http://i1095.photobucket.com/albums/i469/ElectronicMemory/th_DSCN0650.jpg (http://s1095.photobucket.com/user/ElectronicMemory/media/DSCN0650.jpg.html)

Even in sad cosmetic shape from a hard life, and with nearly all of the original parts still installed that old trooper still could muster a picture and sound about as good as when it rolled off the line....Now THAT is build quality!

I love portholes. I have 2 Zenith portholes and one Raytheon porthole.

If you are looking for a relatively easy to restore porthole, I would recommend
the Raytheon. Mine had a very uncluttered chassis and the chassis was
stamped with tube numbers like it was intended to be a kit.

Here is my restoration thread for the Raytheon porthole TV:
http://antiqueradios.com/forums/viewtopic.php?f=3&t=193131

Carl

Tom, that is an amazing set with mostly original capacitors.

Carl

Gotta wonder if the power xfmrs have enough 'extra iron' headroom to be happy running on 50 cycle.

Thanks very much for all your responses, there a lot of useful info here!

I remember reading about a particular set that had flyback issues, but I wasn't sure which. Now I know! I'd still love to own one of these purely because there was never a circular CRT TV in Australia. We only got tv in the late fifties, so most of the cool designs were out of fashion by then. I also tend to think that set designers in AU were more pragmatic in their approach. Most of the sets here are quite boxy and weren't really made to look like furniture. And of course, it wasn't too long before the rectangular CRT became common, so the rounder tubes didn't last long.

Is there a site where I can find detailed info on these by model? For example, which sets had the metal CRTs, which were more reliable and so on? It makes it a lot easier to decide on any I might spot on eBay. Being in the "wrong hemisphere", I don't have access to all the jumble sales and swap meets that I would die for. Which means that my purchase avenues are very restricted.

The other reason it's good to have reliable info is something I'm sure you're all too familiar with. The sellers on eBay don't know much at all about what there selling or "play dumb" when specific questions are asked. I'm sure that's a global issue! It certainly happens here.

The other useful piece of info of course is schematic availability. I can't even get stuff on the Predictas other than SAMs, (which is still very good). The guy selling the CDs on eBay is not accepting any questions and when I could question him several months back, he wasn't interested in selling to me :(

Difficulties aside, I'd love to own one, preferably restorable to working condition, to justify the floor space. I'm sure I'd be the only person in the country to own one, which itself is rewarding. It certainly wouldn't get much use, so mains frequency and temperature rise of transformers shouldn't be an issue. Even picture cut off would be acceptable, I won't be watching anything other than vintage B&W movies on it anyway.

Last point, is it possible to rewind flybacks? Has anyone ever done this themselves or employed a company to try? I've seen the posts about rebuilt CRTs, and the interest in resurrecting this process. But flyback repair seems to be another important aspect because they too are unique and vital to keep a set running.

Just my rambling...


Adam ;)

Is there a site where I can find detailed info on these by model?Sort of, but not all in one place and you'll have to do some homework yourself.

Many models listed here (some might be missing for all I know):

http://www.tvhistory.tv/1950-59-ZENITH.htm

Manuals listed here (same caveat):

http://www.earlytelevision.org/tv_schematic_diagrams_pw_n-z.html

Tube data listed here:

http://tubedata.milbert.com/index.html

The manuals are listed by chassis number, not model number. If you look at a Zenith manual such as that for chassis 23G22, you'll find near the beginning a list that cross-references about 15 model numbers and chassis numbers. Elsewhere in the manual you'll see what CRT a particular chassis uses. Other manuals have more info.

So, you can look at some pictures and say, "Hey, I love this model," and with luck, figure out what chassis and CRT it uses. Then, using the third link, you can look up the CRT's data sheet and read the description to find out if it has a metal or glass envelope. Or, it's possible the manual itself might mention what sort of envelope the CRT has; I haven't read all of those manuals from cover to cover.

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

Thanks very much Phil,

You're a legend! By the way, I've ordered some rest clips from eBay to facilitate work on the Holiday. I'll post pics of them when I've assembled them into leads for running the board away from the chassis. Of course, it will be a rats nest with all the wires in place and I'll have to be careful to avoid shorts.

Cheers and thanks again,

Adam :)

Shipping to Australia would be quite expensive - just guessing.
That along with building a protective crate.
I'm curious, have you got a rough estimate of the cost?

Carl

G'day Adam. I bought one of these sets at a local antique shop many years ago and it is still in queue for restoration. The CRT was just about zero emission and I bought a rebuilt one from a member of the Antique Radio Forum. But as mentioned above, the flybacks seem to be toasted in many of them.

Below is a picture of the flyback in mine. Mind you, I have not tried to apply power yet. I was able to get a Merit brand replacement just in case this one is bad. (Fat chance it is good!!!) It has a 10 AMP fuse in the horizontal section. Any guess why this flyback became so charred? And being below the chassis certainly adds to the heat.

http://i1067.photobucket.com/albums/u435/kvflyer1/Port_fly_web_zps3caecfe7.jpg

And the set which has a 12" CRT, 12LP4:

http://i1067.photobucket.com/albums/u435/kvflyer1/Porthole_zps24ed4267.jpg

So, hope that if you are able to get one, I could pop in and visit with you on my next trip to Melbourne.

Cheers Mate!

My porthole flyback looks VERY similar to the one above. I also have not tried to put any power to mine. Glad I got that NOS replacement - just in case. :D

Al, I think the set picture above is the same Graemere model you got from me. Here's a photo of its flyback which looks a lot better.

https://farm8.staticflickr.com/7144/6393181467_41ef095dd3.jpg (https://flic.kr/p/aJWJ7F)

I think that set is the exact same model Bob! So beautiful. You are correct, that flyback looks LOADS better. I cannot wait to have that set playing one day!!!!!!

Shipping to Australia would be quite expensive - just guessing.
That along with building a protective crate.
I'm curious, have you got a rough estimate of the cost?


No, but I'm guessing around $1000. A couple of years back I bought a Predicta Holiday on a roll away stand and that cost $700 to freight here. It was very well protected and arrived here in perfect condition. But I believe the Pirtholes are a lot heavier than Predictas.

Seeing the pictures of these obviously distressed flybacks raises a question: why do they do this?

Is it just poor circuit design, underrated windings for the job, or is there more stress when metal CRTs are involved? On a humid day, there are more likely to be losses due to coronas and arcing from the metal section of the CRT. Do flybacks in sets using all glass CRTs last any longer? This might seem very far-fetched, but would a liberal slathering of RTV133 on a metal CRT reduce stress on the flyback? Food for thought...

Cheers,

Adam

The few I've seen up close like the one pictured above appear to suffer from deteriorating plastic of some sort. I don't think they're burning up as much as crumbling apart.

Hi Down under!

I am a german collector who is hooked on aussi TVs.
Number #7 (early rare STC) is soon on the way.
Shipping is very expensive and a question of the distance.
Maybe that`s the reason why I am the only one in Europe who
owns australian TVs.
O.K., its the other side from our earth!
WHAT A LUCK that Australia, a partner of the Commonwealth, decided to
introduce the european CCIR standard. In this case I have no problems with them!

The 21" Kriesler console, 100km down from Sidney picked up by the shipper,
crated in a perfect wooden box was a 1600,- Euro gift to me.:puke:
(The smiley says everything!)
This price is incl. customs work, x-ray control etc. because of 9/11.

I have 2 portholes, the 12" Raytheon and a 12" Zenith.
The Raytheon had a factory installed wrong winding on the power transformer.
My transformer man has controlled it and was amused that this transformer lived longer then a week as it was new (totally burned).
The set was a self import from my last US-travel.

As an Aussi you are on the right side when you decide to rewind the
power transformers to 230 Volt.
I can give you for that the new winding numbers!
I have a 50s article (Funkschau) of a german TV repairman who revised in the 50s hundreds of US TV sets from members of the US army in Germany.

When the americans went back, he turned them back into the US standard.

You have more fun with the TVs when you allign them to CCIR because of
the bandwidth.
I don`t think that you are able to produce 60 Hz to run with the US vertical frequencies.
Do you have a NTSC converter from an old US-vcr?

Are you on the way to do this work completly?

These older HV transformers can be rewinded, missing knobs are bigger problems.
American schematics are really good, there is no way to do them better.:yes:

I heard that 12" tubes are often down with there emission/gassy and not so easy
to find than 10" tubes.
Please correct me if I am wrong.

Happy week-end,

TV-Collector :stupid:

...These older HV transformers can be rewinded...
Could you elucidate with a little more details and particulars on that?
Thanks

:yes:

Larry Fine says, damn the flybacks, full speed ahead.

http://i268.photobucket.com/albums/jj7/300cSRT8_photos/Zenith%20G2350Z%20Restoration/Portholes-LarryFine007.jpg (http://s268.photobucket.com/user/300cSRT8_photos/media/Zenith%20G2350Z%20Restoration/Portholes-LarryFine007.jpg.html)

Yes, I like to do it:
-you need a winding machine or you build your own with a low voltage
battery powered drill. Importent is a counter.
-you need some special hoses for the thin wires
-you need a special kind of paper which looks like thin cardboard

The "special stuff" I am talking about is not common to me in english.
I have to find a translation.
My elderly friend workes his hole life in a transformer/electrical motor repair
and construction company.
Nothing he couldn`t fix!:tresbon:

"Modern" HV transformers which are glued like the junk in my Predicta
is not worth to rewind, because you don`t get the glue off to count the windings.

All over the world we are cooking with water, this means that we can
interchange all kind of transformers as far they are similiar constructed.

The deflection angle and the high voltage has to be the same.
Then you have to control what kind of other windins and tabs you have.

In the case of my Predicta Barber Pol I decided to kick out the HV transformer,
which went down south including his glue and the 5 wire deflection yoke
and rebuild it with a Philips system.

If only the HV coil is destroyed (inside or only at one of the ends?)
it can be easy changed.

Since some weeks I work out with the help of my friend how to do
an easy transformer repair/winding change.

I have a lot of japanese vintage radios and TVs, most of my US TVs are rewinded.
My friend did it, but now because of his age he didn`t like to do it anymore.

Now I have to learn from him.:scratch2:

TV-Collector:stupid:

before you fire up an old TV which spended its life for a long time in a wet cellar you have to take the HV transformer out from the chassis and dry it in your oven with about 40-45 Degrees Celsius!
Allow to rest for about 30 minutes!

Do this when your wife is out for shopping! You know what I mean?:twak:

:stupid:

That's very interesting! I wondered about being able to substitue flybacks. The flybacks in the two Predicas I've restored so far are in perfect working order, so no need to replace. I did follow Bob's tip and recoat them with RTV133, a high dielectric strength silicone. Great stuff, and easy to produce a tidy appearance if you wet your fingers with denatured alcohol before smoothing the coating over with your fingers before it dries.

A friend of mine in the UK is able to wind transformers since he is designing and planning to market high end tube amplifiers. He is not happy with the existing range of audio output transformers, so he is winding his own. He uses CNC control of his winder.

It's also interesting to see how the Porthole flybacks are disintegrating... almost as if they used the same Tenite plastic as used on the 21 inch Predictas! Thanks to all who posted pictures.

I have not bothered about converting the power transformers to the AU standard of 240 volts, I just use a separate stepdown isolation transformer. Although I may change my mind later, as my UK friend has offered to wind some for me.

Video signal is from a cheap DVD player, that is able to produce both PAL and NTSC. I put up a post about it a few weeks back. The picture would bounce slightly with the NTSC signal, so I thought I must have had a fault. It turns out that resetting the DVD player to produce a PAL signal and readjusting the vertical hold fixed my problem. US TVs are extremely forgiving in this regard!

The Australian STC set you have would be very nice indeed, and quite rare. Other AU sets that you might want to collect would include brands such as AWA, HMV, Astor and PYE. The PYE Pedigree is a great set, but it comes down to personal taste. I would love to have one, but limited floor space means that I probably will not. The later versions used transistors, so you may need to do your research very carefully if you buy one.

As to doing things when the wife is not home, I understand all too well. That is when I use the stove to heat up capacitor cans for restuffing ;)

Cheers and happy collecting,

Adam