DuMont RA-106 Club 20
 

Earlier this week I was forwarded an email from someone who had contacted Radiomuseum.org mentioning that they had an old DuMont TV (large format) that they wanted to find a home for. Most such contacts don't turn out to be anything interesting, but given that this was a Dumont, I contacted the person and asked for pictures. It quickly became apparent that the set was a Dumont RA-106 Club 20.

I've been looking for a 20BP4 CRT for my DuMont RA-101 Westminster for quite some time, and the RA-106 is the only other model of DuMont that has it.

The set was in Inglewood, CA (Los Angeles area), and rather than simply driving down there to check it out, I contacted our fine fellow VKer Cherokeeroad, who agreed to go test the CRT. His test indicated that there was at least some life in the CRT, which made me rather happy.:yes:

Today I made the trip from San Jose to Inglewood and picked up the set. This ended up being the kind of find one might think is pretty rare these days. The set was in an old mansion (known as La Colina on a street of the same name in Inglewood) which had been abandoned for a number of years. The children of the owner (who had grown up in this house) were cleaning it out and preparing to sell the house. Check out the first two pictures to see the old mansion.

The third picture shows the set in the main living room, where it was currently sitting. The fourth picture shows the corner of the master bedroom where the kids remembered watching the set in the 1960s.

What's terrific here is that the person I bought the set from is the granddaughter of the original owner of the set, and she provided a wealth of information about it. DuMont sold the Club 20 to bars, and this was no exception. It had been purchased in late 1946 or in 1947 for a bar called the Green Cat in Santa Monica. The fifth picture is a copy of a business card from the Green Cat, which I was told opened in 1938 and closed in 1950.

The location of the Green Cat was 4th and Santa Monica Blvd. The building is still there today (see sixth picture).

The person I bought the set from spoke to her father (the son of the original owner) and here is an excerpt from the information she provided about this conversation:

"Just got off phone with my dad. In WWII he was in the radio operators training program for the Navy. When he got out in 1946 he recommended that his parents purchase this, based upon his knowledge of DuMont from the Navy program, to help bring in business to The Green Cat. The bar was located on the southwest corner of Santa Monica and 4th in a 1920s converted former bank building. It was 1 and a half stories tall. The vault was converted to the kitchen. I don't know if it's still there. DuMont was purchased for 950 and installation was another 250. They had to erect an extra tall antenna to get reception past the 4 story Hensheys building. Also, it was late 1946 or early 1947 when it was acquired."

More to follow...

I got the set home this evening, and retested the CRT. A little low on emissions at first, but after cooking with 8 volts on the filament for 10 minutes or so, it's looking pretty decent (see first picture). They apparently didn't run this set enough to kill the CRT at the Green Cat. Having heard that there were memories of watching this set still working in the 1960s, I thought there was a pretty good chance the CRT was alive.

The remaining pictures are self-explanatory. There are two chassis in this set -- one main chassis and the high voltage subchassis.

The dial is quite interesting, with a spiral pattern for the Inductuner. There is a shrouded lamp behind the dial that moves up and down on an elevator mechanism to illuminate just the correct part of the spiral for the particular revolution of the dial that is currently active. That's quite a bit different than the dial on the RA-103. Also interesting to note that even though this is a very early set (1946 or 1947), it does not show Channel 1, even though it tunes down to 48 MHz (all Inductuners were that way, even into the 1950s). This dial might have been replaced at some point, since I found a small piece of what may be a broken dial in the cabinet. So maybe the dial is newer than the set.

And a little more to come...

The family still had the original instructions that came with the set, as well as the card that labeled the controls on the front panel when the set was new.

Interesting that the instructions are just five duplicated pages, made with the purple ink from a stencil on a typewriter, just like the duplicated worksheets many of us used as school kids many decades ago. Sometime soon I'll scan the pages individually and try to bring out the severely faded text so it can be read.

Even the original envelope from DuMont is there.

I'll start working on restoration tomorrow. Hopefully the restoration will go smoothly and we'll have a picture on it soon.

Fascinating! It always amazes me how time capsules like this old mansion get abandoned. When was that house last lived in?
Thanks for sharing this great adventure. :thmbsp:

just think some people hae taken such things and just tossed them before asking around or selling , gems like this are rare and getting rarer

Hey now, I graduated in 2002 and we still used the spirit duplicators reasonably often. I also was not in an excessively poor or low budget school district, I think it was just that the damned machines are more or less armageddon-proof and the teachers had been using them for many decades and it was just part of the habit. I'm thinking it wasn't a coincidence that most of the machines were located in rooms only slightly larger than most home bathrooms are. Cheap buzz. :smoke:


Sadly there's no real non-destructive way to attempt to un-fade them if they're totally gone. Hopefully yours are still dark enough to scan and enhance!

Fantastic find Tom. If the house was abandoned it is amazing the scavengers did not get to the set. Interesting though about the operation instructions. The original "Club" (the one that shares the RA-102 chassis with the Clifton but had a 15" CRT) had its own illustrated operation manual.

It is posted here on Chuck's site: http://www.myvintagetv.com/Apple%20P...mont_RA102.pdf

Wow, not that's an adventure... and to see that old mansion and know the history of the set like that. Congratulations! I second Tim on his amazement at how the house had not been scavenged.

Tom, glad to see you finally found the elusive 20BP4. BTW, the DuMont RA106 chassis was the only one to use the 20BP4, and the Manchu model also uses the 20BP4 in addition to the Westminster and Club 20 . I just took delivery of a Manchu, but my set has had its 20BP4 replaced with a rectangular 20CP4. However it fits almost identically, and no modifications were required to make the substitution. So until I can find a good 20BP4 (good luck!) it will do quite nicely.

Good luck with your set!

That is a great acquisition and fascinating story, Tom. I look forward to your restoration notes. Now, I would think that you have a big question on your hands: Move the 20BP4 to your RA-101 (and move that CRT to the '106), or keep it in this set?

Wow, what a treasure -- with an interesting backstory, to boot.

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

Tom, sooo happy you were finally able to locate one!!!

First, I'll think I'll restore the Club 20 with the 20BP4 in it. After a little time to enjoy it, I'll probably transfer the 20BP4 to the Westminster, and put the 19DP4 sub into the Club 20. It's hard to say which set is more rare -- I'm only aware of 1 other Club 20 out there. There are 2 or 3 other Westminsters, but the Westminster is a more elaborate and interesting set, so I'll give it the edge on overall value and being deserving of the 20BP4.

The Westminster has a much higher CRT anode voltage (18 kV or something like that). That actually exceeds the spec of the 19DP4 in there now. Also, the raster is too small on the 19DP4 in the Westminster. Lowering the anode voltage might not completely solve the problem, since there is some neck shadowing. Looks like the yoke was designed for the 54 degree deflection angle of the 20BP4, and won't work correctly for the 66 degree angle of the 19DP4.

The Club 20 appears to have a lower anode voltage (there is a tag inside that says "Danger 12,000 volts") and that might work better with the 19DP4. I may still have the yoke neck shadow problem, and if so, perhaps I'll try swapping in a different yoke in the Club 20. The Club 20 will be generally easier to work on, since the rear end of the CRT is much more accessible in the Club 20 than the Westminster, with its CRT tilt mechanism.

Progress today on the Club 20: My time was very limited, but I was able to take apart, clean, and reassemble the various gears and linkages in the Inductuner assembly. It was frozen solid. The problem was not in the tuner itself, but in the bearings for the main dial shaft. Turns well now, and I also gave the Inductuner a good shot of De-Oxit, which generally seems to be necessary on these.

I also confirmed that the little chip of plastic I found in the cabinet is definitely part of a dial, and not the one in there now, since it has no chips out of it. So I think the dial was replaced at some point, which might explain the absence of Channel 1 on the dial. (Or is this set a little newer than the 1946-47 purchase date the family cites?) Maybe someone with a Manchu (should have the same dial) can comment as to whether Channel 1 is shown on the Manchu's dial.

The dial on that is the same as the dial on my RA-108 Mansfield. The colors on yours are still OUTSTANDING. My colors have faded. My RA-108 is from 1949. Original ad for the Club 20 located at below link if you scroll down. Hard to tell exactly what dial is on it, but sure looks "busy" like the RA-108 dial and the one you have pictured above:

http://www.earlytelevision.org/dumont_postwar_ads.html

Well, here's the first picture on the big 20BP4. This set came to life without much drama -- just a full recap and cleaning of tube sockets and controls, as well as the mechanical work on the tuner as mentioned above.

http://www.videokarma.org/attachment...1&d=1408770426

The CRT is reasonably bright. The set needs quite a bit of adjustment, and I'm going to have to find a big enough mirror to do it. The depth of this set makes it totally impossible to see the front while adjusting something on the back.

Regarding the color on the dial: The colors are on the back side of the dial, and there is some back lighting in the picture I took. Without back lighting, the dial doesn't show much color.

Nice, quick work, Tom! That looks good.

Here here! What a great set and it's starting to come together nicely. I can't wait to see the totally finished product.

Amazing!!! Great work!!!

Here are some enhanced scans of the Operating Instructions and the Unpacking Instructions that came with this set. These were severely faded duplicated pages (purple ink), but I think they are just readable after scanning and enhancing.

Also, to follow up on an earlier comment I made: The CRT anode voltage in the Club 20 is measured to be 18 kV, which is basically the same as the Westminster uses for the 20BP4. There was a "Danger - 12,000 Volts" tag inside the set, but this does not accurately reflect the actual voltage on the CRT. Probably a tag more appropriate for the RA-105, which has basically the same chassis, but a different high voltage supply and a 15AP4 CRT.

Awesome work! Well how about that regarding the dial! A little back lighting and my colors appeared from no where! Cool!

Regarding the colors on the back of the dial. My RA-105B "Sussex" dial had most of the red and green translucent paint rubbed off.

Testors Candy Apple Red And Green translucent clear paint, available in spray cans are a dead nuts match. Mine looks great.:smoke:

An update on this set. I've been working on it a bit here and there over the past month, and it's pretty well dialed in now. The cabinet finish was good enough on this one that it only needed a bit of Howard's Restore-A-Finish. A few shots of the set attached.

http://www.videokarma.org/attachment...1&d=1413092297

http://www.videokarma.org/attachment...1&d=1413092297

And a few more you can click on...

The set works very nicely now. Its only shortcoming is that the picture is not as sharply focused on the left side of the screen. I find the focus uniformity is a little better with a brightener on the CRT, so I think the cathode center is a bit worn out. Not sure why this happens more on the left side of the screen, but it certainly is better with the brightener. The center of the screen is very sharp with or without the brightener. I will soon transfer this 20BP4 CRT to my Westminster, and will see if the behavior is the same, which should clarify whether the problem is the set or the CRT.

http://www.videokarma.org/attachment...1&d=1413092602

Although this set is very rare in its own right (probably only 2 or 3 left in existence), the real draw is the 20BP4 CRT, which I will transfer to my Westminster soon. Then the 19DP4 sub which is the Westminster will find its way into this set.

The 20BP4, with its very low deflection angle, Pyrex envelope, Frankenstein-type anode connection, and highly convex screen is quite a thing to behold:

http://www.videokarma.org/attachment...1&d=1413092708

Here's a closeup of the label:

http://www.videokarma.org/attachment...1&d=1413092708

Although a lot of DuMont stuff is really high quality. This particular CRT doesn't quite fit DuMont's "First with the Finest..." motto. These glass bubbles in the screen are pretty big, and very noticeable when viewing the set:

http://www.videokarma.org/attachment...1&d=1413092708

I'm also curious as to whether this might be a rebuilt CRT. Since the 20BP4 has a Pyrex envelope, most CRT rebuilders would not have been able to rebuild this tube. Maybe it went back to the DuMont factory? The reason I'm curious is the green glass joint visible in the neck of this tube. An earlier (gone to air) 20BP4 I used to have (the one that came with my Westminster) didn't have anything like this. I wonder if this is a soft glass neck joined to a Pyrex funnel? The green glass might be a matching glass to join the two together. Also note in the label picture above, there appears to be a shadow of an old label, along with the new label, both apparently done by the DuMont factory. Did DuMont do their own rebuilds? Or was this one rebuilt in its original production (failed some test when first built, and was then reworked)?

http://www.videokarma.org/attachment...1&d=1413092708

Nice work, Tom, and interesting notes about the CRT. That green ring is odd indeed.

Perhaps the Bar models got the third rate production CRTs since many of the viewers would be too drunk to notice the imperfections, and those sets would not wind up in the living room of some well to do customer's house like the other 20" models.

I actually think that's sound reasoning. What bartender in a soiled wifebeater and 5 o'clock shadow is going to care about those tiny spots? A lesser amount of character comparing to his own sordid past.

Try a Geiger counter on the green glass ring. Its probably a Uranium glass.
My very old (three Germanium transistor) Geiger counter does register,
barely, on the green glass in Pyrex to soda-lime glass seals.

Very interesting! I don't have a Geiger counter, so I won't be able to check your theory, but it sounds like this type of glass is known for being used to join Pyrex to soda-lime glass. That all makes a lot of sense, and we have probably figured out that this thing was indeed rebuilt with a soft glass neck and replacement gun.

That would seem to indicate that the rebuild was not done when the tube was first made (to correct some mfg flaw), but at some later point. I would guess that if they had rebuilt it when it was made, they probably would have been capable of putting a Pyrex neck on the Pyrex tube. A few years later, when Pyrex tubes were no longer made, a rebuild like this would have made more sense.

With the bad tube that came with my Westminster, I actually tried to get a rebuild like this done. Clinton agreed to rebuild the tube if I could get a soft glass neck joined to the funnel of my Pyrex tube. I got the custom glass piece to join Pyrex and soft glass from an outfit in New Jersey, and got a glassblower here in California to agree to join it, but unfortunately, the glassblower here was not successful, so I abandoned the plan. Seems like it was a good plan, but I didn't have the right glassblower. Anyway, I'm glad to have this 20BP4 now.

Perhaps some CRT tech was attaching the gun and ran into a jam and used a cross cut from a green bottle that held his soda or beer hehe :D

SR

Hi Tom,

Last month I purchased Chuck Azzalina's DuMont Manchu, which has a NOS 20BP4 in it. When Chuck was taking delivery on the set about 7 or 8 years ago, they dropped it when unloading from the truck. Snapped the neck off of it. Somehow Chuck found a NOS 20BP4 to replace the broken crt.

The tube is soooooo impressive. In my conversations with Chuck, he tells me the tube is rather heavy.

I don't intend on removing my crt from the set (no reason to do so) but I am curious; with the tremendous physical size and weight of the crt, How in the heck did you lift it out of the cabinet? And do you have a weight of this humongus bulb?

Please tell us the story of how you removed the tube.

Thanks!!

Hi Bob,

Actually, it's not that heavy. One of the attributes of the early Pyrex tubes is that they are rather thin walled, and the front face is WAY thinner than later tubes. The highly convex front face and high strength Pyrex on the 20BP4 give it good structural integrity without needing to use very thick glass. Bottom line is that it is not particularly taxing to lift the tube out of the set. Something like 25-30 lbs total I would guess.

I can definitely say the 15GP22 in my CT-100 is significantly heavier than a 20BP4. More modern 21" B&W tubes are also heavier than a 20BP4, even though they are far less deep from neck to screen. They are heavier because of the thick glass they have on the screen.

The only thing that was a little scary about removing the 20BP4 from the Club 20 was that it had adhered to the rubber mask. I had to pry it up, and during that operation I worried a little working so close around such a big tube at a moment when the risk of implosion is somewhat increased.

I would sure love to know where people can find NOS 20BP4s these days. Chuck is very experienced and well connected!

An update on this set. Its 20BP4 has now been transferred over to my DuMont RA-101 Westminster, which I consider a more valuable set. I have to admit it was painful to pull the 20BP4 out of the Club 20, since that was its original home, and the set has been working very nicely.

You can read about the Westminster here: http://www.antiqueradios.com/forums/...46908#p2246908 .

Here's a shot of the Westminster with the 20BP4 installed and happily performing its duty!

http://www.videokarma.org/attachment...1&d=1422253615

I probably won't be able to keep the Club 20, since I don't really have room for it in the house, and I don't really like it taking up space in the shop. So I'll install the 19DP4 that used to be in the Westminster in the Club 20, and see if I can find a new home for the set.

Your RA-101 looks great with that 20-inch CRT.