DuMont RA113 saved from becoming an aquarium!
 

The seller told me to take it and make it an aquarium!

I couldn't let this set get away. DuMonts are RARE in western NC.

I will take pictures and post them possibly as soon as this weekend.

It's around a 16" rectangular tube. It has an ion trap on the neck. The back, knobs, and all hardware is there. Someone cut the cord a long time ago. It has a tuning eye. Lots of 7 pin mini tubes.

It is temporarily in residence in my mom's lawnmower shed until I make a bit of room in this shed that I call my house.

EDIT: Ryders sez that it is a 17" tube.

EDIT 2: The cabinet model is Burlingame in mahogany.

Bruce

good save, did you bite your tongue when the fish tank was menitioned :)

I was tempted to back-hand slap the kid... around 16 or so. I resisted, and ended up paying $50 for the set. At least they helped me get it on my truck!

:yes:

I may have this all wrong, but I think that this pix is a '113... if that is the case, it would seem to be a very poor choice for an aquarium... the ratio of "picture size" to the rest of the front of the TV is poor... too many knobs and tuning dials! Did the owner perhaps suggest that the front be opened up?:puke2:

Anyway, great save!:yes:

jr

Good goin', Bruce...DON'T wrassle that thing around by yrself anymore than you absolutely have to in this DREADFUL heat...On my side of the hill, its a balmy 93-94....

Thanks. My set has one set of knobs with the screen to the left. I couldn't see the aquarium idea, either. The one in your pic is a Tarrytown model, I believe.

Up here in the hills, its a balmy 85 right now. It wasnt too bad getting it off the truck. It was laying chassis side down on the blankets, and was easy to grab a hold of... Found about a million spider egg sacks before we put it in the shed. Removed them.:D

I am quite confused about these DuMont models... The TV history site shows 2 different sets as RA113, one like mine (except mine is a 17") and a 19" roundie with the controls on one side.
http://www.tvhistory.tv/1950-59-DUMONT.htm
The booklet that came with mine, indeed identifies it as a "Tarrytown" but with model # RA-113B... is yours an A?

Harry Posters site identifies a 17" one-sided control layout DuMont as a RA-113B "Brookville":
http://harryposter.com/vintagetelevision.htm
Perhaps the RA numbers are chassis numbers and the names are used to describe the various cabinet configurations?:scratch2:

confused,
jr

Found a pic of this set in the Ryders listings. The cabinet is a Burlingame in mahogany.

The model number (according to Ryders,) is RA-113-B5.

The set is located about 10 miles from me right now. I'll be taking pictures on my next day off from work.

I did a bunch of writeups on early DuMont sets for Radiomuseum.org. Here's the story on the RA-113 and its relatives: http://www.radiomuseum.org/r/dumont_...ra_113_b7.html

You can find information for RA-101, 102, 103, 104, 105, 108, 109, 110, 111, 112, 113, and 119 there if you explore a little. Pictures and schematics for quite a few of the sets. Schematics also at the ETF site.

If you see any errors in the information, let me know.

That is one heck of a set!
Does it have a metal CRT?

THANK YOU!
This clears up the the confusion about the various different RA113 models. It also appears that some of the info on the TV history site is in error... the 19" roundie is not a 113 but likely a 112 and the Tarrytown-looking set shown is indeed 17" like mine, not 19" as indicated.
jr

Ps: my RA-113-B7 has a glass CRT...should be a 17AP4, but IIRC, a more common 17BP4 was substituted.

No, it's a glass CRT. Dunno the number of the one in the set, yet, but its all glass and rectangular.

Id love to find a RA-101 set one day. That set-up looked like it was a real hoss with that 4.2KV AC high voltage transformer!

Thanks, Tom for the link.

OK. Here we go. FIRST PICS of the DuMont!

The 2 open back pics are the ones that do it for me. The set is for the most part clean inside. The last pic is inside the HV cage. No signs of damage that I can find. Stuck my nose in there and smelled no burn smells.

Note that the tuner is set at channel 3, or so. I wonder if this set was ever connected to cable, or did it last run WBTV channel 3 in Charlotte NC?

On the chassis, there is no place to connect 300 ohm twin lead. Just a connector that looks like an RCA phono plug.

It also has a phono input. I like that. I have a couple of old turntables I can use here.

The kine appears to be OEM.

Someone at some point cut the wires at the speaker. This was done within site of a nice 2 pin plug that connects it to the chassis. Stupidity? EDIT: Not stupid. Someone replaced the output transformer, but did a sloppy job of it.

Did DuMont buy tubes from RCA? This set is full of silver lettering RCA tubes.

And a few more...

Check out that speaker repair work. Ugh.

I like that chassis nameplate.

See the RCA plug looking antenna connector on the left? Is there an adaptor that I should look for here?

The R5 in orange paint... Maybe this is to identify the chassis to the set?

WOW! thanks for posting the Pix of this rare DuMont! :banana::banana::banana:

No Adaptor or balun... just 75 Ohm coax with a RCA plug. Sorry about the poor scan... booklet is in poor shape with many pages stuck together. :tears:

jr

Somewhere in this disaster that I call home, I have an F connector to RCA plug. I appreciate your booklet scan.

Bruce

Awesome! I love Dumonts. Looks like it's in pretty good condition.

Most TVs had tube replacements over the decades.

Phil

Right, but I would think there might be at least a few DuMont tubes...


OK, there's more to tell. I have the set at my house now. Pulled the chassis and cleaned everything.

Started by testing all of the tubes. 1 weak 6SN7, and a fried 5U4GB. The fried rectifier made me feel funny in the pit of my stomach. All other tubes are good, testing around 90-100% on my Sencore. No leakage either.

The CRT checks about 98% and the needle slowly drops to 0 when I cut the filament power. YAY!!:banana:

Here's the bad part. Started looking at the underside of the chassis and found a fried electrolytic first thing. This is probably what fried the 5U4.

I pulled the spare 5U4 that I had installed, and using my variac, applied about 5 volts to the transformer. Instantly, my amp meter on the variac jumped to 2A. Not good. I looked around the chassis for obvious shorts, found nothing. In the 2 minutes that the variac was turned on with the chassis, the power tranny got very warm to the touch. I can smell it, too. I stopped testing. Im afraid I need a transformer.

See the following pics...

1st pic: The bottom of the tranny that you cant see when the chassis is installed.
2nd pic: General chassis condition
3rd pic: The Offending Cap
4th pic: The source of the stinking burning smell. The smoke is rising from the hole the wires come through.

OUCH! :tears:
Have you tried disconnecting all of the secondary leads from the power transformer? Long shot... the 6.3 V heater voltage could be shorted to ground somewhere, or the 5U4 socket could be charred from arcing. I sadly agree, however that the transformer is likely fried.
jr

What are the spec's for the transformer?

John

Sams sez:
760Vct @ 260ma
5V @ 3A
6.3V @ 7.4A
DuMont #20005011, Stancor #P-6134, Merit #P-3074
jr

Update...I posted the wrong PNs... the above are for the isolated damper filament transformer... the correct numbers for the power transformer are:

DuMont # 20004711
Stancor # P-6315
:o

From the Ryders, its:

115v primary

secondaries:

5v for rectifier
380v w/center tap
6.3v for about 22 or so tubes, and kine

(The sweep tubes have their own transformer for filaments)

For now, I hope to find an original type. I know Hammond sells some fine trannies.

Thanks, JR TECH.

My transformer is fried. I disconnected the secondaries, and turned it on with the variac. Smoke...

My Ryders lists the transformer from DuMont as a 20004771

Oops! You are correct... I posted the PNs for the damper heater transformer.

Sams Sez (if I look in the correct place):

DuMont # 20004711
Stancor # P-6315

Sorry,
jr

Jr. Dont be sorry. Now I have the Stancor numbers! Thank YOU!

This one looks more like a regular transformer, some DuMonts used the huge Sola transformer.

I have some transformers I pulled out of some RCA's, one is from an 8-t-241 I think the other is a 9-t-240

If someone can cross those to the Stancor numbers or check on the voltages maybe one will work.

Found a 9-T-240... Sams shows:
770Vct @240ma
5V @ 3A
5V @ 2A
6.3V @9A
Stancor P-8152

pretty darn close!
jr

I have a Thordarson 26R71, but it's only 600VAC CT.

John

Being rated 240ma... could make it run warm? Mine is 260ma.

How about the 10v difference in plate voltage?

Very Interested in this, if you guys think it will work! I missed a Stancor P-6315 on eBone by a few days...

If you think it'll work you're welcome to it.
Some of the rag wiring coming out of it is a little rough, might need replaced.

I can take pictures tonight.

I notice it has two 5v windings where yours only has one, I'm guessing it's for the Damper heater.
If you don't use that it might make up for the 20ma difference.

I really appreciate the offer. I bet the 2nd 5V winding was for a 5Y3 rectifier, as alot of early sets had more than one rectifier.

Are the wires fairly well marked as to what they are? I dont want to blow up my set... I've replaced wires on a tranny before.

Bruce McGee

By not using the 5V 2A winding you lighten the load by 10 watts... also the 6.3 of the RCA transformer is 9A, while the DuMont is designed for 7.4A, so that winding will not be running at full load, another 10.1 watts lightening of the load.
The additional draw at 770V from .240A to .260A is only 15.4watts, so the transformer could actually run cooler. DuMont tended to over-design, so the actual current draw in the B+ may be somewhat less than 260ma.
I would consider adding a couple of plate resistors in the 5U4 plate leads or one resistor in series with the input choke, to drop the extra 10 V.
Are the dimensions/bolt patterns similar?
jr

While you're searching for a new transformer, this is an ideal time to replace all of the electrolytics in the power supply. Or, at least replace that burned-up cap before you power it up again :)

Phil

My tranny is about 3 3/4" X 3 1/8" more or less. The measurement is mounting bolts center to center.

I have a 6.3v filament tranny rated at 14 amps. I tied it to the filament circuit.

Everything except the Hz output, and damper lit up. It was nice to see this.

Output and damper lit up when I disconnected one of the primary leads on this fried tranny and applied power to the set.

EDIT: I am replacing all electrolytics and many other caps before this set is turned on. Im going to store the cabinet and bring the chassis inside for some work.

Another EDIT: Lost my mind and listed both the hz output and the damper as being on the 2nd transformer. Only the damper is on that tranny.

Odd!:scratch2:
My Sams schematic shows that the second power transformer (T-2) is only used to supply heater voltage to the damper diode (6W4) heater, and that the Horizontal output tube (6BG6G) is connected to the "normal" non-isolated heater circuit (from T-1) as all of the other tubes, with one side of the heater circuit grounded. What does the Riders show?
jr