The 30" CROSLEY TV RESTORATION

[ohohyodafarted]

Nice job on those schematics John. That must have taken a lot of time and patients to trace and draw. Good Job!

[John Folsom]

Thanks Bob. A great deal of my career as an electrical engineer was spent using various drawing editors to generate schematics and PCB layouts and fun simulations, so this was familiar territory. The program I used was from a PCB fabrication company, ExpressPCB (http://www.expresspcb.com/). They supply free software to drew schematics and lay out 2-sided PC boards. The software runs on a PC, or in my case , on a MAC running PC emulation software. I used this software a few years back to design my 'personal color wheel viewer' that I displayed at the ETF.

Steve McVoy used the same software to generate the schematic of Nick's prototype color TV, and Steve was kind enough to let me use his library of components he had created (tubes etc). This made my job a bit easier.

The software is easy to learn, and easy to use, so if any of you want to draw a schematic and/or lay out a PC board, check them out. They have a pretty extensive library of pre mace components, both analog and digital, and it is easy to create custom symbols and shapes in the schematic editor.

PS I noticed a bunch of errors in the reference designators on my posted schematic. Fixed 'em, will update them the next time I make my next update.

[Penthode]

Hi John,

Wow: this is an amazing set. Looks like you are going to have lots of fun with this one. I will stay tuned for more.

I reviewed your drawings and I spotted one thing I cannot figure out. It looks like you specified for V10 a 6BQ6 for the vertical output. The control grid has a 500ufd/ 50volt capacitor on the control grid I cannot make sense of. The 500ufd would have to me been more appropriate as the cathode resistor bypass capacitor.

Terry

[cwmoser]

John, your reference to the Express PCB Schematic software piqued my interest. I downloaded it and it runs on my Linux desktop too using "Wine".

One thing I did notice is that it lacks Vacuum Tube symbols. Did you custom create those symbols or is there a library I can import?

Thanks

Carl

[John Folsom]

Terry, Oops, my bad. Once you make a mistake, it can be hard to see it. Yes, that cap should be on the cathode. :-)

Carl, send me an email address and I will send you the custom library with conponents tha Steve McVoy and I have created.

[holmesuser01]

This is nothing short of exciting. I've never seen a 30" B/W CRT set in my life.

I've only seen one 27" B/W, and it was a Magnavox, and was weak, even with a brightner.

[old_coot88]

Originally Posted by holmesuser01

I've only seen one 27" B/W, and it was a Magnavox, and was weak, even with a brightner.

Every 27" I ever seen was flat as a pancake, as well as every 24" (all Maggies).

[Eric H]

Originally Posted by old_coot88

Every 27" I ever seen was flat as a pancake, as well as every 24" (all Maggies).

I think it has to have something to do with the size, painting a bigger canvas with the same sized brush and all plus higher 2nd anode voltage pushing it harder.

[dieseljeep]

Originally Posted by 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.

John, is that the set I sold you many years ago? I'm refering the low-end chassis model. The same guy I bought my set from, also had a Crosley set like you're showing. That set had a 1952 model Admiral 27" chassis in it. The original chassis had a burned up flyback in it, and was scrapped.

[dieseljeep]

Originally Posted by John Folsom

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

IIRC, Admiral used the magnetic focused 27" glass CRT's. RCA was famous for the 27" metal cone CRT. Magnavox used the electrostatic focused glass CRT's, to the mid-60's. The last one being the solid state B&W chassis. All were 90 degree deflection.

[WISCOJIM]

Originally Posted by John Folsom

...the RA119B1 has a conventional click tuner, flyback, and a very pedestrian design.

John, did you ever trace out the schematic for the RA119B1 or ever find any service information on it? Is it similar to any other DuMont you've come across? I still haven't attempted restoring either the RA119A or the RA119B1 that I still have in storage.

Also, does anyone have an idea of how many of these 30-inch sets still exist? You and I have the only RA119B1 sets that I know of, and you have the only Crosley I've heard of.

[John Folsom]

Well, wiscojim, if you are Dave Nash, the answer is yes. Never did find any documentation for the set, but recapped it anyway. Now that I am drawing a schematic for the Crosley, I probably should do the same for the 30" DuMont. When/if I do, I will get you a copy. I have heard of a handful of 30" DuMonts. Steve McVoys ETF website shows 8 in his database. Probably a few more out there, but not a lot more.

[dieseljeep]

Originally Posted by John Folsom

Well, wiscojim, if you are Dave Nash, the answer is yes. Never did find any documentation for the set, but recapped it anyway. Now that I am drawing a schematic for the Crosley, I probably should do the same for the 30" DuMont. When/if I do, I will get you a copy. I have heard of a handful of 30" DuMonts. Steve McVoys ETF website shows 8 in his database. Probably a few more out there, but not a lot more.

John! I'm Dave Nash, AKA known as dieseljeep on this forum and also A-K. My beloved Diesel Jeep Liberty is in Jeep heaven now. Rust in peace.

[John Folsom]

Well then Dave, I am kinda confused. Who is wiscojim?

[David Roper]

wiscojim is the guy who didn't sell you RA119B1 he has--and dieseljeep is the guy who sold you the one he had.