The 30" CROSLEY TV RESTORATION

[John Folsom]

The next big project (literally) is the restoration of my 30" Crosley TV, featuring the 30BP4 CRT. I have had this set a number of years now, and it has been lurking in the corner of my garage hiding under a big red bedspread. I had decided not to take it on until now for three reasons. First, its 30BP4 is a dud. Second, top of the cabinet is in poor condition, and will need refinishing. A skil which I do not possess, and am not likely to acquire. And third, I have never been able to find documentation for the set.







With the recent news of RACS in France possibly closing their doors this summer, I contacted RACS through Jerome Halphen to see if they would rebuild the tube. Alas, the word came back that either the tube would bee too big to fit in the over, or if it did fit, it would be too close to the heating elements. This news finally motivated me to do something I have been putting off for a very long time.

I have a spare 30BP4 up on a top shelf in the garage, but it tests quite weak on my trusty Beltron CRT tester. But the 30BP4 in my 30" Dumont Royal Sovereign does not test all that good either, and it makes a presentable, though not very bright, picture. So I decided the only thing to do was to pull the spare 30BP4 down and use the DuMont set to drive it and see if it was worth the effort to use it for the Crosley set.

Being a lazy guy, I really did not want to demount the CRT from the DuMont and install the spare. So I used the bottom canister from the shopvac as a test stand and put the CRT face down on the canister.



This worked out very nicely, and after a bit of configuring, I powered it up. Nothint. I adjusted the ion trap, still nothing. I checked the HV; a generous 17KV. So I flipped the ion trap over and after a bit more adjusting.... hot dog!



It may not be the brightest tube, but it is good enough. So I made the commitment to take on the Crosley. I made another attempt to find documentation for the set, checking (again) Riders and Sams with no luck. The Model # on the set is E-30 COBU. I have a marketing brochure which shows an artist line drawing of the set, with the Model # EU30COBU (or EU30COMU).

If any of you out there has any info on this set, I would appreciate hearing about it. To be continued....

[John Folsom]

Continuing... I decided to pull the sweep/power supply chassis and examine it, as it looked unusual. It turns out to be a rather unique configuration,
with separate transformers driving the sweep and HV. I also noted that the whole chassis was put together with nuts and screws, no rivets.
It also has no tags, labels, ink stamps or markings of any kind.






The TV chassis is clearly a more conventional production chassis, though some sort of a modification of what was probably a standard B&W production chassis.
It uses rivets, but once again, has no stamps or markings, other than one little paper label which proudly proclaims the chassis is union made.
All of this leads me to think I will likely not find any documentation for the set.



As I would be a bit reluctant to start recapping the set without a schematic to fall back on, I resolved to trace the wiring and generate a schematic.
Here is the result. The only unknown I found was one crisyp carbon comp ½ watt resistor, shown as R? on page 1, in the B+++ side of the primary of T1.
Does not look like it will be any trouble to S.A.T. a value for it.

I have reposted the two power supply schematic pages in a later post in this thread.

Next, I will generate a schematic for the TV chassis, containing the RF/IF/video/sync/V&H oscillators. To be continued....

[leadlike]

John, this is all very interesting! I always thought that the Crosley was a rebadged Dumont. Am I to understand that this set does not share the same chassis as the Royal Sovereign? Also, very nice to see one of these sets in the flesh. I have only ever seen print ads for the Crosley, never the real thing. Do you know of any other collectors that own a 30" Crosley?

[John Folsom]

leadlike, as you may know, the Royal Sovereign came in two versions. The RA119A featured a RF HV regulated supply, a continuous tuner, and a very deluxe design (as DuMont was wont to do). The second version, (my set), the RA119B1 has a conventional click tuner, flyback, and a very pedestrian design. The Crosley design is their own. The TV chassis is very similar to some other Crolsey B&W sets of the same vintage, but the HV supply (I believe) is unique. I am really looking forward to getting it restored and see how it performs.

[Phil Nelson]

Zowie!!!

If it makes that kind of picture without any recapping, it should be an easy restoration. Just keep your forklift handy

For such a rare item, I would definitely look into having the cabinet done. There are quick/easy things that can blend minor boo-boos and improve the appearance a lot, if you don't want to invest in a total refinish.

Regards,

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

[John Folsom]

Phil, The CRT was being driven by the 30" DuMont chassis (which has been recapped), not the Crosley chassis (which have not been recapped). Still, I foresee no real problems restoring the Crosley, just he usual work of replacing wax paper caps and restuffing electrolytic cans. I WILL have the cabinet refinished.

[Phil Nelson]

I get it.

Just looking at that giant red CRT gives me a backache.

Phil Nelson

[Eric H]

Originally Posted by Phil Nelson

I get it.

Just looking at that giant red CRT gives me a backache.

Phil Nelson

If it's like other Metal/Glass tubes it probably doesn't weigh all that much but I've never handled one bigger than 16"

[leadlike]

The 30" tubes don't weigh very much. I remember KX250rider made a post about handling a Royal Sovereign as well as the crt, and he noted how surprisingly light the metal-glass crt is. Certainly the 16" one I handled out of my Zenith seemed totally featherweight compared to an all glass one.

John, I wasn't aware that Dumont made a "cheaper" version of their Royal Sovereign sets. Kind of disappoints me since I only thought they dropped continuous tuners and robust build quality after Emerson took them over.

As an aside on 30BP4s-so few are found today, and even fewer that test good. Did they have a tendency to deplete their cathodes faster than say, a 12" tube did? They certainly shared the same type of gun, but the 30" had vastly more screen area to light up than any of the other B&W crts ever did.

[John Folsom]

The 30" tube is big, awkward and scary to handle, but not all that heavy. The tube was stored above my head on a shelf in the garage. The scary part was standing atop a 2-step footladder, embracing the bell of the tube, lifting it to point the neck of the tube past my head and over one sholder, and wobbling back down the 2 steps. Whew!

If you look at the photo of the CRT behind the DuMont, you can see the cheaper version chassis. Very conventional.

As for the life expectancy of the 30BP4, I just don't have any data on the subject. I would speculate that not a lot of sets were made using the 30BP4. Seems like DuMont only produced that tube for 2 year(?). Maybe longer for renewal reasons. Or they may have offered rebuild services. The urban legend is that all the metal cone CRTs had a higher failure rate than the all glass CRTs. Seems probable, but I have not seen any reports or articles on the subject.

[W3XWT]

Hi John... The "bourbon legend" on the 30BP4 is derived from the 15GP22. And, from what I've heard from those blessed (cursed?) to have had to work with such is almost universal based upon being a metal/glass hybrid. (What was the original hybrid? The mule!)

One thing about the Crosley, have you ever though about trying the IUE local(s) in the Cincinatti area or nearby to other Crosley plants? Perhaps a retiree may be a source of schematcs or at least info...

[John Folsom]

INteresting idea.... but from down here in Florida, I would not have a clue how to deal with the IUE in Cincinatti.

I have pulled the TV chassis. It appears to be a modified version of their 21" model in Sams 186-3. Going through the video IF, so far it is identical. But I ams sure I will find some differences, and will end up drawing a schematic, as it would be too hard to try and mark-up the Sams to document the changes.

[jr_tech]

Originally Posted by W3XWT

Hi John... The "bourbon legend" on the 30BP4 is derived from the 15GP22. And, from what I've heard from those blessed (cursed?) to have had to work with such is almost universal based upon being a metal/glass hybrid.

But the 15GP22 has an additional "weak spots" that the 30BP4 does not have... the welded flange on the 15GP22 appears to be the major source of leaks. IMHO, one of the problems inherent in the metal cone tubes is the limited getter flash area, as the metal cone allows only the use of getters in the neck rather than the funnel. Much less getter flash area is obtained.

jr

[Glenz75]

Wow...This is going to be an interesting restoration project John, will be following this thread for sure!
The largest black and white CRT I've seen is 25 inches in diameter. I have a couple of TVs that use them and both give a very nice picture.
Cheers
Glen.

[John Folsom]

The next biggest B&W CRT was the 27"... I think there were at least 4 versions made by various CRT makers.