Found the DuMont I wanted, now what?

I went looking for a DuMont Mt Vernon about 6 months ago, and I found one in LA, but I live in NYC, so I didn't go for it.

But a month or so ago, at my twins' birthday party, one of the fathers is looking at my Dynaco and Bottlehead gear and mentions he has an old tube TV that his grandmother had left to him when she passed away last year at age 97. It turned out to be a DuMont Mt Vernon, the same TV my family had when I was a child. I've identified the model name from my searches on ebay, but I don't know if there's a number associated with it. The owner knew it hadn't been used in about 20 years, as that was when they bought her a modern set. The power cord practically disintegrated when we moved it to take the back off, where he showed me how they unplugged the cable 20 years ago from the picture tube so it wouldn't be used.

The set appears to be in good condition physically, but I'm a newbie at old TVs, even if I could rewire my ST-70 with my eyes closed. Is this set worth anything? Is it worth restoring? It'll be a nice piece even if it doesn't work, but it'd be really cool to have it working. It's not the 30" monster, but it was big for its time. My mother dates it to 1951 as that was the year my brother was born.

Anything else anyone here knows about this one? I'd post a pic, but I don't have it in my house yet, and I don't have a digital camera either. I'm picking it up this coming weekend.

[wa2ise]

Does he know if the set was working (with a picture on the picture tube) when it was replaced with the newer TV set? If so, all you should need do is replace all the wax caps, and possibly the electroytic caps.

[bgadow]

While it may work as is you would sure want to "soft start" it, using a variac or dim bulb tester. Its a sure bet that at least some of the caps are bad anyway. I don't know this model off hand but I'm sure its worth saving. DuMont went down hill as the 50s went on but I think this one is early enough to be one of the ones built like a tank. I have some factory service information to lend if you should need it, covering many of the earlier DuMont sets.

[Frank]

The DuMont Mt. Vernon used the RA-112 chassis with the 19AP4 CRT. Service lit. is Sams set 119, folder 5. The date was 1950-51. These sets had problems with audio IF transformers. There were many revisions during production runs. Check DuMont Service News for details.

Frank

I just spoke to the grandson that I'm buying the TV from. As far as he remembers, the TV hasn't been moved from the spot it was in since at least 1960.

As far as I remember, the set did have audio problems, with a loud hum that would start after it had been on for about 15 minutes. If we switched from TV to FM to Phono, it would stop for a while. Countless repairmen came to fix it, but nobody ever did. I think that was one reason it went out.

And thank you everyone for the suggestions.

[Tubejunke]

I gave away an RA-109 a couple of years ago. I kind of wish I could have kept the thing as it was about the most well built and interesting set I have ever owned. The metal crt was neat and the monster chassis looked like a christmas tree with thirty some odd tubes lit including dual high and low voltage rectifiers. The darn thing was just too big and heavy to mess with. With its great wooden doors and brass lions head door pulls it was a rich folks set when new and even today you would need a large home to house such sets. Especially if you have a few others. Something had to go. I robbed the tubes and turned it over to a probably better fate than sitting out in a shed. The man I gave it to was supposed to fix it. I hope he did. I would love to find a table model Dumont roundie. I'm trying to avoid consoles as are many folks.

I picked up the set today, and was lucky to have a neighbor help get this thing in my house. It is BIG and HEAVY. I spent the rest of the afternoon with my wife moving furniture around to find a spot for it, which we never really did. Ultimately we decided it was too big for any place we had, but when I opened the doors we agreed that it didn't look quite as imposing with the screen showing as it did as a big box.

As Frank suggested, it is an RA112 chassis and the picture tube was also marked RA112, but I don't doubt that the 19AP4 number is correct as well. I spent so much time moving furniture that I don't even want to move this out again to see.

The cabinet is in near perfect condition, and I hope the picture tube is too, but only time will tell.

A question for all of you. Is there a way to check the picture tube without going through the trouble and expense of fixing up the rest of the electronics first? And besides the caps, which can be a problem, and of course bad tubes (I can get almost any tube), what else will be a weak point. Wiring? Trannies? Resistors?

[Sandy G]

Capacitors. I'm no repairman, but they're likely to be yr #1 problem.-Sandy G.

[Eric H]

No point in repeating everything, here's a link with some good info on soft starting your set: http://audiokarma.org/forums/showthread.php?t=34920

If someone near you has a CRT checker it would be usefull to check the tube.
A 19AP4 is about as hard to find as a 15GP22 I think.

Thanks. I was reading through it last night. I know who to ask about a crt checker, but is that something that is portable? I'm not moving that set again!

One other question. Should it have a fuse on the AC? I didn't see anything, but I didn't look too hard either.

[bgadow]

CRT checkers are portable, not much bigger than, say, a Sears catalog. I think most models would work. You don't want to just check the filament, you want to get a reading of how strong the tube is.

Off hand, I would say it won't have a fuse. Maybe in the high voltage. Adding one, if it doesn't already, wouldn't be a bad idea.

[mbates14]

doubt it, ive had a 19ap4. before i foudn the right tube for my emerson. its long gone though. gone to air.

I've bought the Sams folder for the set and now I'm sure I'm over my head with this. Over 100 caps, 100 resistors, 40 chokes, 25 tubes. The parts list doesn't identify which caps are electrolytic and paper and I can't go by the picture. I can see some multi section can caps but I'll have to open it up to take a look, no small job in itself.

[polaraman]

Just worry about the electrolytic caps/cans, paper caps and any black beauty caps. Any resistor over 1 meg should be looked at. That would be your start and go from there.


polaraman

How much current would something like this DuMont draw? I see some 5amp Variacs for sale on ebay for not too much money. Is that enough?

Never mind. It says 2.01 amp @117vdc. in the Sams folder.