The Family DuMont
 

Howdy all,

Here's a couple photos of the DuMont Ardmore my grandparents bought new back around 1950. It's been one of my dreams to get it working again since I was about 15. I'm now 49. I think it's time I get to work, what'cha all think? :yes:

As an admirer (never owned one) of Dumont telesets, you have a great project.
There are some real experts on these.
Good Luck.

Most you come across, have the case with the doors. This one is an interesting change and must be rarer.

Great set.

Appears to be an RA-108 variant. I'll be working on one myself over the next couple months.....get your soldering iron ready :yes:

Where are you from?

I'm out in Farmington, New Mexico, up in the Four Corners Region near Utah, Colorado, and Arizona.

You'll be working on a RA-108? Excellent! Vintage televisions are pretty rare out here. In fact, vintage ANYTHING is rare. Pretty much everything "vintage" has to be imported! I've never seen another DuMont Teleset in person (except for maybe in a museum). Seems a lot of folks have high regard for them. I know my grandfather said DuMont was pretty near top of the line in it's day. They seem to be well regarded around these here parts (Meaning the forum)! Except for maybe the 19AP4 CRT!

First order of business is going to be a full recap. Looks like about 50 or better caps including electrolytics. Tuner has seized (it still turned when I was 15!), hardened grease is likely culprit from what I've read. It's going to be a learning experience for sure! As for the CRT, since I don't have any specialized testing equipment, some luck is going to play into it. I know the heater filament is good, but that's about it for now. I'm beginning to doubt that a bad CRT was the reason the set was retired, but a lot can happen in 50 more years. I've got my eye out for a spare CRT already.

New roll of solder and a new soldering iron tip are at the ready!

-Cary

Yep, sadly right now the set is in the garage. I brought both chassis in the house, and plan to get the rest of the set in the house and into the basement after the Christmas tree is disassembled and the living room crap can go back in the living room ;)

The way things are going around here, I'm going to have DuMonts coming out of my arse soon :D . Here's the thread where I got this one a month ago. It's going to my friend Al, it was his mother's childhood set :)

http://www.videokarma.org/showthread.php?t=260099

Thanks! I don't have much to judge by, since other than photos, this is the only DuMont I can remember ever seeing. Looking at photos of different DuMont sets, though, it does seem the ones with doors are more prevalent. The cover of the "John F. Riders" service guide shows six models for 1950, and four of them have doors. Interesting that out here in the west, as dusty as it is, that my grandparents would buy one without doors. Although where they lived out in California it was all citrus orchards and vineyards "back in the day", so maybe dust wasn't as big a deal.

ALMOST looks like a Royal Sovereign...THOSE are VERY rare..

Man, I'm gettin' jealous of all the vintage sets that seem to be piled up back east! DuMonts everywhere! We just got our Christmas stuff down yesterday, and put away today, so we've got to put all the furniture back where it goes, and then I'll have room to at least get the chassis over here (the set is stored in a building right across the yard) and start start working on cleaning up the tuner while waiting for parts to arrive.

Almost, but it's not nearly large enough to be that. :no:

I just looked at this:

http://www.earlytelevision.org/dumont_ra-119.html

And now I have TV envy. :jawdrop:

My friend has the same Dumont that you have except his might not have the metal grille over the speaker grille cloth.
I have the RA-110 and it too is the type without doors and the tuning dial is at the bottom not the top and it too is square

that RA-119 has 45 tubes total and draws over 5 amps when playing , that must be one nice picture , the biggest roundie and black and white set ever.
mike

I think this has come up before, but does anyone know if any of the 30" Crosley sets have survived?

I believe 1-2 are known to exist, and I believe there is a restoration thread here on one of them...

I know of a collector in St. Louis who has one. He is a member here but doesn't visit much.

I'm having to crawl with the capacitor replacements on my RA-113 with the rectangular screen. BUT, every time I replace a few, I've noticed changes on the screen, and the sound.

I love all the room there is under the chassis on a DuMont.

Happy to hear it's going well for you. That bolsters my confidence! The replacements for my missing tubes are starting to arrive. Got my capacitor order in today with "Just Radios", including the three 470pf 15kv caps that seem to be only available from him. I kicked around using high voltage ceramics, but figured ordering all my caps at once from Just Radios was a pretty good deal, including getting the HV caps that are guaranteed to work well. Also ordered the micas for the Horizontal output circuit, since it seems they are troublesome.

I was just joking with my wife that even if it turns out my picture tube is toast we should end up with a big ole' decent FM monaural radio! :lmao:

Ordered my caps from JustRadios in Canada. I know they get pretty good reviews, but I'm not sure about dealing with Canada Mail. Just found out if I want a tracking number, it costs an extra $10, so after dealing with JustRadio's Microsoft EXCEL ordering system yesterday for quite a while yesterday before I got a file they could read, I just found out they pulled my order from shipping today waiting to see if I wanted to pay the extra $10 or not. I guess I got spoiled by Antique Electronic Supply's ordering system, which is pretty easy to deal with, and of course, tracking is free. Man, I REALLY wish we still had a LOCAL electronic supply store!

I've ordered from Just Radios a few times and it's always been no problem. The problem with shipping doesn't really seem to lie with Canada Post but rather the US Customs service. Which is why the delay. Or so I've been told.

John Folsom has a restored 30" Crosley.

Good to hear. I haven't ordered anything out of Canada in recent memory. I usually skip Canadian EBAY auctions because shipping is so high.

I agree many problems seem to be on the United States side. I have a tube for a 1945 Minerva radio floating around out there somewhere. Shipped before Christmas from Pennsylvania, and last tracked leaving Lehigh Valley, PA Dec. 26th..and it disappeared from radar after that.

A tube for my DuMont project wasn't shipped until the 27th out of Wisconsin, and I got it yesterday.

Most of the problems we've had with mail lately were because of our local carrier, and a tracking number is nice, because it keeps them on their toes, particularly when they mark an item as "delivered", and it's not in my mailbox!

Still waiting for my capacitors to show up in the mail, but we've got the DuMont in the house and I noticed the speaker is going to need a "re-cone". I've never done that before. I've done a little searching on the internet and found companies that will do the recone, and that's definitely an option, but does anyone know of a good supplier for a recone kit or parts to do it? It's a Jensen P10 speaker.

Found some added info: The SAMS says a Quam 10A4A speaker is a factory speaker as well. I wouldn't be opposed to replacing the whole speaker if I knew a good equivalent substitute.

Thanks!

Does the speaker really need reconing, or does it just have a few holes or rips?

I have successfully patched speakers using tea bag paper and flexible glue. You can buy a special "service cement" made by GC but many people report success using flexible glue from a craft store. Some people even use coffee filter paper. Your TV's audio section is not a high-fidelity system; a patched speaker will sound just like the original.

Tea bag paper is so light that it will blend in pretty well with the speaker material. If that doesn't satisfy you, you could darken it with a magic marker but I would not paint the cone.

Just an idea . . .

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

People lament the demise of local parts stores for small electronic parts, but I gotta tell you in general the local stores charged multiple times higher for the same capacitors and resistors you can get mail order, or internet order. We still have ONE local parts store that inventories capacitors and resistors (not Radio Shack), and their prices are high enough that I use them for emergencies only. And, they are a wholesale store.

Howdy Phil!

Thanks for the idea on fixing the cone. I might be able to give the repairs a try, but I have a feeling it's toast. It's pretty crumbly. I noticed the speaker cloth on the front of the set bulging slightly and it's because there's chunks of speaker cone or foam resting in the bottom of the cone, against the cloth. Pressing lightly against he cloth, it's pretty "crunchy" sounding, and there are at least three places where the cone is cracked through right now. I'll have to pull the speaker to take a closer look. I might be able to get enough of a repair done that it will put out some kind of sound at least, when I get to that stage in the operation. There is certainly no hurry on the speaker, just want to line up a repair or replacement ahead of time while I'm stalled waiting for parts.

Thanks again!

If there is a foam ring that is supposed to bind the outer edge of the cone to the frame then I believe there are re-foam kits available.

EDIT: If it is truly toast measure the resistance of the voice coil and buy a speaker that has the same mounting dimensions and voice coil resistance if it is a PM type...If it is a field coil type then it gets more complicated.

Different sizes of new cones are cheap. Cut away the old cone leaving about an inch of old cone still attached around circumference of the voice coil, glue in the new one. The ones sold below have foam surrounds which might cause a problem with "bottoming" of the voice coil on loud bass so it might be necessary to devise a way to stiffen the surround a bit.

http://www.electronix.com/advanced_s...r+cone&x=0&y=0

Howdy!

Thanks for all the great advice! Especially the stuff about the speaker. The supplier for the replacement cones is great!

Finally started working on the set in earnest. Here's a photo of the cabinet after the cleaning with GOJO, and treatment with Howards "Mahogany" finish restorer and several applications of Howards "Feed n' Wax". I didn't want to do a complete strip and refinish, but it looked pretty ugly and "dried out" before, so I didn't know what I was going to be able to "get away with". Turned out pretty presentable, I think, without losing it's "oldie" charm.

Interesting to me was finding my grandparent's telephone number from the 1950's, starting with the "TR" exchange, written on the cover to the HV section. (As in "TRinity5-2437") Put there to ID the set while in the repair shop, my guess. I remember when I was little my grandmother was on a party line, and the only reason she got a "private" line was because, over the years, everyone else on the party line got private numbers! She was the only one still on the party line for years, getting the cheaper rate, until sometime in the late 1970's the phone company discontinued party lines and started charging her for a private line.

I was worried that the tuner might have a stripped/broken gear, since the knob would turn about a third each way and then bind. I knew to never force it, but we've had kids in the house over the last 20 years, and THEY didn't always know not to force it. Good news was the only reason it was binding was because the string had broken and was stuck in the gear teeth in a couple spots, causing the bind. I'd read about the dreaded "fiber gear", but it looks like the gears in my tuner are all metal.

Everyone around here who's looked at the underside of the chassis has found it pretty intimidating. The biggest recap I've done is on an RCA 99K console radio (1938), and it turned out good. This appears to be about twice that, so if I think of it that way, it's not so scary looking!

Mystery Tube! That black metal tube center-left in first photo has all the numbers rubbed off..and the photos in the SAMS showed a small glass tube in that spot..6AH6 video amp tube.

Glad I got the "Production Changes Bulletin" with the old SAMS folder..it shows that tube was changed to a 6AC7 tube on chassis code "R" and later. If anyone needs the production changes bulletin, let me know and I can scan it and sent it to you.

There was a tube in the tuner that I thought was wrong too, and was ready to order the one shown on the parts list, then got to looking at the changes bulletin and saw that the "mixer tube", 6AK5 on the parts list, was changed TWICE during later production runs...first to a 6BC5, and then to a 6BC6...and the 6BC6 is what was in that spot. That's when I figured out that the letters stamped on the back of the chassis are "chassis codes" that coincide with production runs shown on the changes bulletin. Mine is stamped "AM", which coincides with the last change on the list. Seems to denote that my set is from the last production run, and has every single change made..now I'm going to have to look over my capacitor list and see if I ordered any wrong due to production changes! Live and learn!

Second photo is of tuner string squirrel's nest after I "unclogged" it from the gears..looking close, the middle gear on the shaft MIGHT be fiber! Glad it didn't get chewed up!

Cary,
I'm truly awed at this project, to be restoring such a rare heirloom handed down within one's own family.
Wonder how many here are old enuff to remember the dreaded fiber timing gear in the Model A Ford engine.:D

You can usually find the tube number embossed in the metal part that surrounds the octal plug part of the tube.

Thanks. I took a look but don't see any number there. It's a JAN military surplus tube, apparently Ken-Rad..Ken is visible, "Rad" is worn off. The only numbers on it are a "V4", and "SC961A", but I haven't found any cross-reference to that number. There is also a barely visible "2" like it's the end of the a number, and cross reference to a 6AC7 is an 1852, so that's a possibility. Visually, it does appear to be the correct 6AC7, and the heater pinouts match, so I'm going to figure that's what it is for now since I don't have any reason to think someone would have put the wrong one there. It's the only metal tube in the TV, and apparently the 6AC7 is only available as a metal tube. I've now seen photos of the embossed number like you mentioned, and this tube definitely doesn't have one.

Recapping has begun! No turning back now....

A vanishingly rare 6AC7GT was produced. There is at least one vendor selling them for a very reasonable price; it's tempting to get one or two for experimentation to see if they are at all suitable for use in TVs.

Your set must be an early version. My RA-113 has a 7 pin miniature tube in that spot.

I've got a couple of used 6AC7 GT's here, according to my lists. Don't know if they are good or not.

According to the SAMS Photofact, production changed bulletin, your set might be earlier than mine. SAMS says: "To accommodate tube availability the video amplifier tube, V9 was changed to a type 6AC7. The tube socket wiring was changed when the 6AC7 tube was used." (I'm no expert, but that last sentence seems kind of obvious...since the tube it replaced was a mini glass tube and the "new" replacement uses an octal base.)

The bulletin doesn't give dates, but serial numbers and some chassis codes. Apparently this change was made on the 112A at #1232254.

The bulletin also seems to indicate that the change was only made on the RA-112A. There's nothing in the SAMS production changes bulletin that says it was ever changed in the RA-113. Don't know why they'd change it "to accommodate tube availability", and not change it across the board.

Military tube then the number missing is VT-112


Chuck

a-HA! Thank you!

Yesterday was a marathon recap day! I'm not a very fast solderer, I have big hands, a 30 watt iron, and can't friggin' see close up through my glasses anymore (I'm resisting bifocals). And some of those caps are in VERY tight spots, particularly the two that were in the metal box in one corner of the chassis..it took forever to finagle those out and then in again.

I still have the HV section to tackle today, but I feel I'm on the downhill side!

Here's a couple noteworthy events:

The parts list in the SAMS photofact appear fairly accurate. In general, in replacing the paper caps, I ordered one or two spares of each, in case I screwed up and ruined some, and that's about what I ended up with. EXCEPT the .05 value. I ordered 11 of them, and I'm pretty sure I ordered at least two spares and maybe three, because it uses far more of them than anything else..and I only have ONE spare left.

I will say this: I didn't take into account the productions changes bulletin when I ordered caps, primarily because I didn't think of it until after the order was placed, so that could account for coming up "short"...glad I ordered extras!

There are a couple other values that I have extra leftovers of, and that might coincide with the "shortage" of .05's.

MOST notable is that I came up one short on 10uf 25 volt electrolytics. There is only one listed on the parts list (I didn't order any spare electrolytics, primarily because of expense, and not being familiar enough to know what I might use in the future, and I might lose them down the road anyway...you should see my shed..I figured they're a tad more durable with their aluminum housings, too) Turned out there's one in the "main chassis", and there there's another one "hidden" inside the aforementioned metal box in one corner of the chassis. The SAMS photofacts photos show it there, with the cover off the box, but there is nothing at all denoting it's existence. None of the usual arrows corresponding to SAMS location numbers point to it. Seems it was missed somehow. I didn't find it in the production changes bulletin either. Luckily it's a value that our local Radio Shack appears to stock, for a couple bucks, so I'll go get one today and get it in there.

Evidence of prior replacement caps: In one case, location C2 on the SAMS, calls for a 50uf 150 volt electrolytic. What was actually there was a 16uf 150. It's listed as a "filter". Don't know the result of such a change, but it's back to the value as listed in SAMS. I'm sure it was an early replacement, as it was soldered to a cut "pigtail".

There was also a couple older plastic caps in there. A HUGE Mallory .5 "Plascap" and a plastic Sprague.

Pretty much every old paper wax coated caps was "gooey". I saw in a previous write up by someone that they had to get the residue off their hands with Boraxo. I keep Boraxo around too! Works wonders!

I did not "restuff" any of the old cardboard or aluminum caps, but did leave them in place for aesthetics. Frankly, I'm not completely confident in my abilities, I've never worked with multiple can caps before, and figured if something goes haywire in the power up, I wanted to be able to see, smell, and hear what was going on...and having everything out in the open will make replacement in that case easier.

Here's a photo of what appears to me to be a couple of obvious failures:

Been my experience that some of the worst looking caps still work. You just never know.

You didn't leave the old caps in circuit, did you?