Any one have info on this TV?
 

Looking for any info on this TV.
Real, fake ?
With so many knobs, why if not real?

This was in a living room photo on the cover of some home decorating magazine in the late 40's. I have the full photo at home and will try to post later. Pure design fantasy.

It's fairly obvious that it's fake, but that's a neat concept that Philco's engineers likely saw and used as the inspiration for the famed Predicta Barber Pole. Among other reasons why it would have to be fake, there appears to be no provision for servicing the CRT neck area to make critical adjustments such as yoke, focus coil and ion trap position. As the technically-inclined are well aware, these adjustments require access to the tbe neck while it appears that the only way to reach the CRT is by pulling it out from the front on this "model", which certainly would make these adjustments extremely difficult.

There would have to be a seam in the "bonnet" that encloses the CRT...then you could lift the top part off and access the CRT adjustments.
Someone should try building one of these today, like one of us TV collectors...just use a 10" round CRT. Although, the woodworking would probably take a lot of work.

Most definitely the woodworking would require amazing skill. Not the least of which would be required for arranging a means of securing and disengaging the top half of the CRT cover for access without any screws, latches or hinges being visible from the exterior. It's a great concept, though. Any master craftsmen among us who could accomplish this feat of engineering without investing hundreds of thousands of dollars in the making of a single set?

On my profile page is my site that shows I have started to clone this set.
I will be using a 10" electrostatic crt so no adjustments would be needed. The CRT housing started life as a CONGA drum. The table top is being made at a wood shop.
A plywood place in CALIF. has pre made 24" plywood tubes for sale. 27.5 tall 24 inch DIA.
AS a section is completed I will post to my site.
http://home.earthlink.net/~dchoinski/
http://www.aitwood.com/catalog_table..._cylinders.htm

Prewtv:

I was just going to reply with a post stating that I would take on the challenge to build this set (after I complete a few other ongoing projects) but I then saw your post. What a great idea to use a drum and an electrostatic tube! I get back to Milwaukee a few times a year, too bad I couldn't work with you, I could build the base unit.

Steve

Oops! I forgot about the few 10" electrostatic sets that were produced and that such tubes were excellent candidates for this application. Problem solved.

Ha! I was, honestly, about to suggest a Congo drum!

This has the makings of quite a nice set.

Yes...had thought an electrostatic 10" CRT would work but didn't know there were any made. They must be fairly rare.

I guess they are rare but had good luck to find one on Ebay and no one was interested.
http://cgi.ebay.com/ws/eBayISAPI.dll...tem=2597143596

If you mean below the plywood tube, all the wood shops I have shown the PIC. to think there is no base, that the 4 legs just extend down below the tube?
If anyone thinks different would like to hear your ideas.
Thanks for the offer of help. I still have many items I need help on like the speaker grill area. The slats are rounded and on a round surface. I do not know how to do that and several wood shops had no answer.

Pwretv:

By the base I meant the entire thing under the picture tube housing (cabinet, knobs, speaker, chassis and everything else).

Steve

The main things I'd be concerned about with a 10" electrostatic CRT is what its maximum anode voltage was, whether that voltage was enough to produce a bright raster on a 10" screen, and perhaps whether a 10" electrostatic tube with a post-deflection anode might be available (obviously a better choice for high-brightness displays from an engineering standpoint).

The old Tektronix scopes used an interesting circuit with an approx. 5" CRT where the cathode was at about -1250V and the Second Anode ran at about +8.5kV ... beam current being supplied from an approx. 10kV RF-type HV supply. The HV circuit, IIRC, consisted of a 12AU7 (Osc), 6AV5 (Pwr Amp) and five subminiature 5642 (Multiplier) tubes producing about 10kV from 100kHz RF.

The tube you bought on Ebay may be a 10HP4

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

Regarding the proposed tube complement for a 9kV RF supply, a pre-war tube complement such as 6N7 (or 6SN7), 6L6G, and 8016 (early Industrial precursor of 1B3) could be used. I believe American engineers may have developed RF oscillator supplies pre-war and either developed the flyback method as part of radar development during the war, or learned the technique from others.

I would need to do some research to determine whether a 10" round electrostatic tube with post-deflection acceleration was part of any manufacturer's product line.

Some years ago, I had a chance to pick up a Dumont oscilloscope complete with mobile rack. Although offered for free, I was unable to get anyone to transport the thing 40 miles to my home (I was about 19 at the time, no car, living with parents). That was an interesting scope, perhaps a 10 MHz bandwidth. Its claim to fame, however, was its MASSIVE rectangular screen of about 17" diagonal. Also it was a two-piece device. The scope itself mounted in the sloped top of the rack and its power supply was a separate unit occupying the bottom few rack spaces underneath. About the same time, I did manage to pick up an old USN surplus Dumont scope (date printed inside was 7/1947 IIRC) with an interesting "heads-up" display that was covered by a hinged lid when not in use. That one, I later sold to a collector to raise enough for a down-payment on an engagement ring. This was perhaps ten years prior to my meeting Jan. Incidentally, Jan was the first of the many ladies I had met to ever understand my vintage electronics fascination enough to actually learn to share in it.

I won a TV on ebay cheap and might use that chassis.


http://cgi.ebay.com/ws/eBayISAPI.dll...tem=3086643531

I have the Sams on a Belmont 22A21, 22AX21, 22AX22,
those chassis use a 7JP4 or a 10HP4 with little or no change to the chassis. They interchange? Will try 10HP4 on chassis from ebay. I also have a 2 section Sentinel chassis that uses a 7JP4 that might be used.

I think the7GP4 and 7JP4 have the same pin connections. You can't damage your tube by trying it, since they use the same filament voltage.

I finally found the magazine cover photo that started all of this.

Are there any 10" round electrostatic tube with post-deflection acceleration? My books only list 2 10" round electrostatic tubes and they are like the 7JP4. I have a 8" round electrostatic tube with post-deflection acceleration but it has a green screen P31.

Is there another PIC inside the MAG that shows the tv working and maybe has some text on the TV?
Would you sell the mag or copy of pages on TV?
Thanks for post.

The cover photo was emailed to me some time ago. I don't have the magazine. I'll search the home computer tonight and see if the mail is still there and find out more.

If you're only going to use the chassis from that 19A11, what price would you be asking for the cabinet? I have a working 19A11 that's currently in a pretty rough cabinet and has non-original knobs that the eBay seller put on it. I even have an original Masonite back for the thing with an intact power cord, but can't use it with the cabinet I have since the screw posts in the cabinet are history. PM me a price plus estimated shipping to ZIP code 44483 if you're interested in selling that cabinet.

As soon as I get item and get a chance to look it over and see if i will be using it I will send you the estimate.

A note to all the folks trying to figure out the access to the crt and some other details on this photo. This photo, lifted off of my web site by prewtv without my permission, was dramatically damaged in a flood 11 years ago. I spent the better part of a week part time, easily 3 mandays, on the Macintosh rebuilding the lost sections of the image. Almost 30% of the image was lost, including all details of the rear of the crt housing as well as the mount of the housing to the top of the cabinet. All of the details now on this photo are my best guess, and not necessarily correct. I did have the additional advantage that I have a photo of the set, in B&W, from the magazine article, that shows a smaller but relatively undamaged shot from which I gleened some information. This photo shows the set with a test pattern, which can of course can be faked.

About two years ago I drew up drawings for the replication of this set, including mag deflection crt access, as scaled to fit a 10" crt. It will be a while before I get to this project so good luck and best wishes to those who try!

This photo is why I am in the TV collecting hobby, and I saved the magazine it is enlarged from from the trash several times when parents wanted to house clean. Just wish I could have saved it from the '93 flood!

Marlin

Sorry. changed my logo to tube I own.
Found place with AMERICAN HOME mags ask about buying this special edition. All other uses of your pic will end in about a week.
Again sorry.

Dave, I emailed that photo to you a long time ago.
prewtv, thanks, and to show all that their are no hard feelings here is a post of the original full size enlargement before I restored it. Please note that you can just barely see a line at the top rear of the crt housing that MIGHT be service access. Or a way to change the bulb if it was a fake. If I can get the badly damaged mag apart I will post a picture of the tv with a test pattern displayed.http://www.studio4-17.com/supertvb4.JPG

OK TV folks, here is the entire spread of the article. Sorry about the large file size. Note that the same photo as is on the cover is reproduced, somewhat smaller, in the article. http://www.studio4-17.com/spread.JPG

...and here is the close up of the B&W shot:http://www.studio4-17.com/testpattern.JPG

Still can use help. I am not a wood worker.
I repair electronics for cars at Delphi.
So when it comes to wood I am crude.
Under the table top I am using a pre made plywood cylinder 27.5 tall and 24 DIA, 7/16 thick. It has veneer on the out side. Need ideas on how to attach to top, legs chassis,ect?
Could you send me any ideas?

If you are not experienced with wood working it would be wise to first make some drawings of how you think it should go together, then build a rough model of the set to start out with so you can determine experimentally the best way to put everything together. I would not start out buying fancy stuff like with veneer because it may get messed up if you find that what you thought might work-- doesn't. This is not an easy product to start out with in cabinet making.

Keep in mind that this set is not really a cylinder, it is more like a portion of a cone that is inverted.

Since the mounting of the Admiral 19A1X chassis chosen for the set is via four screws through the chassis bottom, a vertically-mounted, removable "shelf" would be necessary. The chassis would be bolted to the shelf and then the shelf would bolt inside the cylinder such that the front panel control shafts would extend through holes in the tabletop. Adjustments for brightness, focus, horizontal and vertical hold would need to be considered preset "service" controls unless some means were provided via dial-cord type linkages to facilitate the operation of these rear-apron controls by means of front-panel knobs. Otherwise, there would be no access other than through the back or bottom of the cabinet for making such adjustments. Raster Size, Linearity and Centering could easily remain as "service" controls. In fact, the Vert. Lin. control was a bit of an "afterthought" on the 19A1X series. None is shown in the original Sams literature. A subsequent "Production Change Bulletin" (part of Set #106 IIRC) shows this control added to the circuit.

Philo Farnsworth developed the flyback HV supply in the early 1930s and was issued a patent for it in 1936.

(Farnsworth patent #2,059,219 "Generation of the High Voltage from the Horizontal Scan Frequency" issued Nov. 3 1936).

Farnsworth may have been the first to apply a flyback for use in televisions, but a very strong argument can be made that Tesla actually invented the basic device.

His air core coil is essentially a flyback, and even the Kettering point ignition system owes much to the Tesla coil.

Anthony (don't get me started on Tesla! LOL)

Thank you for locating the specifics on the flyback supply. As I suspected, it was an American inventor who developed the system upon which circuit designs for television HV supplies are still based today. The fact that the 6L6-driven flyback HV supply of the Farnsworth (listed in the Sams index as Capehart) 610P, 651P & 661P was obviously a part of the original prewar schematic makes perfect sense given this information. The set's postwar modifications which were incorporated prior to its reaching the market in 1948 included a 13-channel tuner (suspiciously similar in its circuitry to that of RCA 630TS), replacement of the original AM sound channel with an FM circuit, horizontal AFC circuitry which was located on a separate chassis, and the aluminized-screen 10FP4 picture tube. Anyone who has access to Sams Set #95A will find the schematic for this model included in that packet. The almost-exclusive use of prewar octal tubes with the exceptions of the few miniature tubes in the tuner, video det, video amp, audio IF and horiz. AFC strongly suggest that set was a prewar prototype with some postwar modifications. It is also noteworthy that one of its two 8016 HV Rect. tubes appears to act as half of a doubler while also performing damping action in the output plate circuit. Although I am not certain of that, it does appear upon looking at the schematic that this is the case. I have not actually worked on this chassis and thus have not had the opportunity to analyze waveforms to confirm my suspicions. I suspect, however, that if a scope, a 100:1 HV probe and a 661P chassis were set up for analysis there would be some clipping of the plate pulse through the action of the 8016 diode which would tend to damp high-frequency oscillations during retrace, producing the smooth sawtooth current required for proper sweep. Having only an EE Tech degree, as opposed to a full EE degree, I can only speculate. Math studies for my degree ended with basic Calculus, so I lack in-depth understanding of Laplace (sp), Fourier (sp), or Differential Equations. Basically, I was trained to be an assistant to engineers.

IIRC, Tesla was one of the many Christians forced to flee prior to the coming of the atheist Bolshevik death squads in Russia, which is what brought him to America in the first place.

Don't get me started on the 65 million Christians murdered over there between 1917-1945 and how my great-grandparents were among those few who managed to escape with their lives before the Iron Curtain would have trapped them. I owe my very existence to the fact that the 1905 Bolshevik Invasion and some rarely-mentioned earlier attempts to implement Marxism failed. I hold a special contempt for the likes of Trotsky, Lenin, Stalin et al and for the modern-day American neo-Bolshevik elements who are currently de-industrializing my beloved America while nullifying the Bill of Rights and establishing atheism as the official religion here in direct violation of the Establishment Clause of the First Amendment after their success in violating the Free Exercise Clause with the banning of prayer in schools some time ago. Stand up for your country, punch a traitor ... lol

The weak point in the pre-war designs was the available tubes for VHF use. These included the 1852 and 1853 octal metal RF types used for RF amp, mixer, and IF amp. These types will not work above 100 MHz, and are the main reason why pre-war tuners were low band only.

There is an interesting article in RCA Review (1946 I think) about wartime tube development. New VHF types were needed immediately for radar, and the first design was the 6C4 in 1942, followed by the 6J6 in '43, quickly followed by the 6AG5, 6AU6, and 6AL5.

When the war ended, RCA and others had millions of these new types in surplus, and they were just what was needed to upgrade the pre-war TV designs. In 1946 the RCA 630 used (3) 6J6s in a new tuner design that added the high band channels, and 6AG5s and 6AU6s in the IFs. The 807 was given an octal base and became the 6BG6G, but the 5V4 damper used in 1939 remained. Even though all TV manufacturing halted during the war, TV design did not. The upgrades were added to the designs during the war as the new miniature tube types became available, in preparation for post-war manufacturing.

The only prewar set that we know of that used a flyback HV supply was the German E1: http://www.earlytelevision.org/e1.html

Farnsworth may have patented the flyback supply, but there is no evidence that he used it prior to 1948.

Farnsworth had TV prototypes before the war, but didn't manufacture any TV receivers until 1948. Before the war, the Farnsworth company made radios and radio-phono consoles. Some had the Farnsworth name, and some had the Capehart name (Farnsworth and Capehart merged in 1938).

Top is started. Did not make as thick as orig?
It is 1.5 inches thick.
Plywood tube is here, they came in 27.5 length, might be too long?
Conga drum for CRT housing should be done next week.
Large wood bowl be here next week?
Have site with PICs also
http://home.earthlink.net/~dchoinski/