Gilfillan Prototype Set
 

Sorry this took so long, been busy as heck at work getting ready for various inspections.

Here's the 21" color prototype I won at this years convention auction, in all its 300lb wood cased glory, enjoy.

http://miniman82.4t.com/images/Gilfillan/IMG_4496a.JPG

Unfortunately the CRT is dead, pay no attention to the tag.

http://miniman82.4t.com/images/Gilfillan/IMG_4493a.JPG
http://miniman82.4t.com/images/Gilfillan/IMG_4495a.JPG
http://miniman82.4t.com/images/Gilfillan/IMG_4497a.JPG
http://miniman82.4t.com/images/Gilfillan/IMG_4503a.JPG

I love the style of the set.. Probably one of the most earliest sets I really like.. Just not too crazy about doors being on a TV set... What year you think it's from?

Shes lovely, great score :)

Very nice-looking set, Nick. Is that a hinged panel giving access to the underside of the chassis on the side? I have seen a similar feature on a Hoffman Colorcaster 4021A from 1955. That appears to be an original design as opposed to a CTC-4 or 21-CT-55 duplicate.

Gilfillan was always a higher end product. I didn't remember them making television sets, let alone color sets.
I was surprised to see they used that el-cheapo Sarkes-Tarzian tuner.
The same PITA tuner that Warwick used in the Silvertones in the mid-50's. :sigh:

I am surprised as well to find out Gilfillan made TVs. I see Gilfillan radios every now and then on eBay or CL, but this is the first of their televisions (color, yet!) I have ever seen. Since this set is a prototype, however, I'm not surprised. It may have been manufactured in very limited numbers, so this one is probably one of a very few such sets in existence in the United States. It may have been made very shortly after RCA's NTSC color television system was commissioned here, so I would not expect to have found very many of these TVs anywhere.

How could this Gilfillan TV be an original design, when RCA had a corner on color TV production in this country? :scratch2: It would have had to use inventions of RCA, as no one else was making color TVs at the time (early 1950s). The chassis would almost have to be an early RCA one, such as CTC2 or CTC4.

The CRT should be easy to find, if the original is dead (no emission? Open filaments?). I cannot imagine the 21AXP22 being so rare, even today, however, as to be unobtainable. Worse comes to worst, you could always get one from a junker set, not necessarily RCA; I'm sure other TV manufacturers used round CRTs in their early sets as well until the mid-1960s, when rectangular tubes became popular.

BTW: I had no idea, until I read dieseljeep's post, that Sarkes-Tarzian television tuners were cheap ones. I was under the impression for years that S-T was one of the better makes of tuners. What made them "cheap"? Flimsy designs with cheap plastic parts, underrated components that failed after only a very short time, or . . . ? I can see such tuners being used in cheap 1970s-'90s pre-DTV portables, but good grief, not in high-end sets. After all, I am sure Zenith and other well-known TV manufacturers would not have been caught dead using cheap tuners (or other cheap parts) in their TVs in the '50s.

When color TV was new, RCA made available the special needed parts. These
really included only deflection yokes, convergence coils, and horizontal output transformers, though others
could get the color transformers as well. Everything else could be standard parts, at least for sets using 21AXP22s and later CRTs.
RCA actually encouraged others to make their own designs. They didn't care ... they'd
get the royalties anyway. At least, if any of the sets actually sold.

Nice score, Nick!

RCA did not hold patent on all possible circuits that could demodulate color. GE had an earlier 15GP22 based set that used their own original chroma demod circuit that did not use an oscillator (and GE kept using that thru the end of the tube era). Look at some of the 60's designs like Zenith's beam gate demodulator or Motorola's (or was it Admiral?) single tube self-oscillating demodulator....The former I would not be surprised if Zenith had designed back in their 1954 prototypes. Magnetic convergence was also a Zenith design (RCA's 15GP22 was electrostatic convergence, and they would have kept making them had others not passed them by). The QAM color signaling method it's self was Philco's idea. The reason most makers went with RCA clones is that it was usually easier/cheaper than to make it your self....At least until profitable volume was selling.

Yes, there's a catch on the inside of the cabinet and you lift it up to open the door. Pretty damn convenient, if you ask me.

It's somewhat of an original design, I'll explain with a bit of a history lesson.


After the CT-100 came out, an almost instantaneous size war erupted between the manufactures of color sets. The only exception was the brief segue into higher technology in the 15" realm with the 15HP22, which printed its phosphor dots directly onto the curved faceplate vice having a flat dot plate as the 15GP22 did. This innovation was quickly put to use by CBS to create the 19VP22 19" CRT, and we were off to the races. This would have been circa mid 1954 or so.

Later that year 19" sets started showing up in the market place (it was CBS and later Motorola and Hoffman making the sets), and it became evident to RCA that something had to be done since 15" sets were now obsolete and no one was buying them. So they embarked on a development program leading to the issuance of a document called LB-962, which was their report on a developmental 21" set in September of 1954. A link to my scanned copy which was included in the Gilfillan documentation is below (warning it's more than 20mb in size):

http://miniman82.4t.com/images/Gilfillan/LB-962.pdf

From the documentation, it's apparent to me that there are stark similarities to the CTC-4 chassis. So why did the CTC-2B show up instead of the one shown in LB-962? I can only assume that RCA knew they had to come up with something fast, because they were being beaten at their own game by other manufactures. Being that the chassis shown in LB-962 was in its developmental stages at that time, I suspect what happened was this (from an earlier email to Steve McVoy):


27 July, 2015:

"My assumption right now is that the reason the 21-CT-55 came before this one was that RCA had piles of Merrill chassis laying around from the CT-100 run, so instead of retooling the entire production line to suit the prototype outlined here they opted to modify the CTC-2 to support a 21" CRT. We have to remember that the 'size war' was in full swing at that period in color TV, and there had to be considerable pressure on RCA to get something to market which could compete with the 19" sets that had come out earlier that year from CBS and others. So I'm assuming they took left over Merrill chassis, slapped in the horizontal section from this prototype (the flyback looks identical to the one in the 21-CT-55), and sent it out the door."



It's the only explanation I can think of that makes sense. Interestingly this LB-962 document still calls the CRT by its developmental designation C-73685, and since the 21-CT-55 came out a few months later and used a 21AXP22, that places the emergence of the 21AXP22 CRT somewhere between Late September and early December of 1954. The date code on the CRT in the Gilfillan is 52nd week of 1954 and it's a 21AXP22 not a developmental tube, so it's in the right ballpark.



Anyhow, back to the topic at hand.

Gilfillan must have applied to get on board with the RCA developmental 21" program at some point, because their circuit is very similar to the one outlined in LB-962. Not identical, but very close. RCA was known to work with other people in developmental programs (see the history of the NTSC color signal, the panels were made up of manufactures across the entire TV spectrum, pun completely intended), so it makes sense. They got a copy of LB-962, changed a few things so as not to get caught up in patent infringement disputes as is still the custom in industry today, and made the set you see here.

Documentation states only 6 were ever built, I'm unaware of any others turning up.

Holy crap talk about rare!

It's got next to no emission, even at 8 volts. I just got 3 electron gun assemblies in the mail though and I'm heading to the ETF next week tube in hand... :thmbsp:



Can't comment on the quality of the tuner, I'm not a tuner buff. It seems to click solidly when I turn it though, so they at least made the detents decent. lol I suppose we'll find out just how good it is soon enough, I'll probably have to do a full alignment on it when I get the chassis recapped. This one has UHF built in, nice feature for a prototype set to have in 1954.

First things first, I have to deal with this:

http://miniman82.4t.com/images/Gilfillan/IMG_0101a.JPG

Yes, rare indeed.

There were 6 space shuttles built, and I've seen three, so rare indeed. :D

Looks to me you've got a JIM-DANDY new Playpretty... W/your technical smarts, I expect to see it makin' "Glorious Lollipop Color" very soon... (grin)

[QUOTE=miniman82;3139645]It's got next to no emission, even at 8 volts. I just got 3 electron gun assemblies in the mail though and I'm heading to the ETF next week tube in hand... :thmbsp:
Regarding my opinion of the tuners: the S/T tuners always seemed to be used in the lower end TV's of most of the big manufacturers. The tuners of that era of the Gilfillin color set, the tube sockets would crumble and the tube couldn't be reinserted. The later S/T tuners had the coil sticks, where the plastic retainer would crumble and the sticks would fall loose and the customer would try to turn the selector and break up the individual strips. Most of the time, the tuner was damaged beyond repair. The problem was generally related to the excessive use of tuner spray. :sigh:

[QUOTE=dieseljeep;3139673]I always considered Sarkes-Tarzian stick tuners (60s/70s) to be the best, and those crummy Shogyo or Oak wafer-switch or turret (some RCAs) tuners to be the worst. PTS used to charge more for an Oak rebuild of your unit - they always seemed to have a fairly good inventory of rebuilt Sarkes tuners, making me think the S-T tuners were more reliable and were low-demand for rebuilds.

As to the S-T stick retainers breaking, it was early Delrin, coupled with the orientation of the tuner - tubes not completely vertical (GE) or a cover over the tuner area (Maggie consoles and entertainment units) that blocked the heat from escaping, baking/browning the Delrin plastic. GE owned up to it with a Service note in the 1970 TV service guide. They showed how to order the turret with newer (bluish) Delrin retainer and replacement instructions. Pull the tuner, dismount it from the cluster, remove sticks that ain't broken, pull F/tuning shafts and wishbone/gearing, slide off the UHF switch, pull the spring, slide out the turret, compare to the new, and reinstall, reversing the steps. At 16 years old, I thought I'd do one myself, got into trouble with the spring, and had to get bailed out by Dad. Oh, if I had only had the instructions...:D

Nice to hear! I hope you are able to put your time off, and your knowledge from RACS, to good use.

Well...sice TWO of them exploded...you will never see them again..I saw at least one on the pad my self --I THINK it was atlantis--May 1999 IIRC.

I do know of another one in existence. In speaking with the owner of that set he believes all six were in different cabinets as well which would make each one "one of a kind".

You should have your friend post his up, we could make it a Gilfillan only thread.

So here's how I decided to repair the flyback, whose wax tire had decided to fall off in chunks over the years.


First a before shot, all dirty and nasty. This flyback is unique just like the one in the 21-CT-55, because it has one of the filament windings for the rectifiers right there on the tire. There are also 2 other filament strings, wrapped around the ferrite core. I think it had to be done this way, because there simply wasn't room elsewhere.

http://miniman82.4t.com/images/Gilfillan/IMG_0101a.JPG

Ah, that's better! All cleaned up with q-tips, Goof Off and alcohol, took about 2 hours.

http://miniman82.4t.com/images/Gilfillan/IMG_0103a.JPG

Amazing it came out that clean, there was actually a nice looking transformer under it all.

http://miniman82.4t.com/images/Gilfillan/IMG_0104a.JPG

Next I removed the bad sections of remaining wax and squared them off, using a soldering tool to melt it which was pretty smelly. Then I built a sort of cardboard trough around the remaining good section of wax tire, sealing the edges where it met the transformer with bits of wax. I poured 2-part silicone into this to make a mold.

http://miniman82.4t.com/images/Gilfillan/IMG_0111a.JPG

Looks like it came out good, but how well had I captured the original profile? Pour in some wax to make a test casting! This is monocrystalline wax donated by John Yurkon, it matched the melt point and hardness of the original stuff pretty close but not the color.

http://miniman82.4t.com/images/Gilfillan/IMG_0112a.JPG

Looks like a match!

http://miniman82.4t.com/images/Gilfillan/IMG_0113a.JPG

Next step, position the mold carefully around the windings and pour:

http://miniman82.4t.com/images/Gilfillan/IMG_0114a.JPG

The result looks pretty good.

http://miniman82.4t.com/images/Gilfillan/IMG_0116a.JPG

Only thing is the original section of wax was slightly angled, and that transferred to the mold. That meant the new wax was slightly misaligned, as you can see where it meets the original wax. It's not bad enough to matter, I think this new tire will work just fine.

http://miniman82.4t.com/images/Gilfillan/IMG_0115a.JPG

Can you enlighten me on the specifics of the two-part silicone you used to do this? I have a whole list of things it would help me with. :yes:

It was a kit from the hobby store specifically for making molds, it just happened to be a 2-part silicone. The name of it is alumilite quick set RTV silicone rubber, worked really good and the hot wax didn't phase it at all.

Great job Nick! I looked this thing over at the ETF, I was amazed at how solid and heavy it is. I can't wait to see a picture on it :)

Nick may have mentioned this Gilfillan color prototype was from the late Ed Reitan's collection. I was in Ed's Los Angeles apt. helping with the moving of various items to the ETF when the movers wrapped up this behemoth and w/a dolly managed to get it down the many narrow steps from apt. to street, to moving van. The set does weigh every bit of 300 lbs. and is built like a bank vault. Ed managed to acquire the set when he worked for Gilfillan Corp. in their military radar division.

-Steve D.

Thanks Steve, I intend to put up a video of this set playing those nice clips a few of the guys put together of his life. Should be a fitting tribute to our friend, and a nice way to cap off the restoration.

The HV cage is 90% reassembled now. The rewaxed flyback is installed, so are the rectifiers. Thanks to WISCOJIM for providing a new socket, to replace the one that had an ear broken off. All HV wiring has been replaced with 40kv stuff from Belden, hopefully there won't be any sizzling to deal with. I decided to replace the coin base GE brand rectifiers with period correct fat base RCA ones, now all the tubes in the cage (aside from the focus rectifier) are fat base T-12 style glass and it looks killer.

Last issue to deal with is the lack of a focus control. Right now there's just a bleeder network coming off the focus rectifier, a 3A2, with a tap after a few fixed resistors for the line to the CRT. There is around 15 megs of resistance to the string, which is more or less what the schematic calls out besides the fact that 5 megs of it is supposed to be in the control. Anyone have one of those special 5 meg focus pots they could donate? I've tried using a normal pot before (on my CT-100), but they always arc over.

Something like the one in the 621TS should work, but there are other sets using a similar style control.

http://miniman82.4t.com/images/Gilfillan/IMGP6723a.JPG
http://miniman82.4t.com/images/Gilfillan/IMGP6724a.JPG

Nick,

Your restoration looks to be a first class job. Ed would be very happy with your efforts. Those focus pots are not easy to locate. Steve K. replaced the pot in my CT-100 with the best substitute he could find. It has since failed. Also, as you know that particular pot has the longer shaft. I don't know if that is a requirement in the Gilfillan set. The Ed Reitan memorial tributes would be a fitting video to display on a set Ed Valued so highly.

-Steve D.

Steve,


I know they can be tough to find, I may end up having to buy a donor chassis or something. Do the 8TS30 and 630 use the same pots? I can make a shaft extension if need be, won't be a problem.

I find the 621TS, to be a rare bird, using electrostatic focus, high voltage at that.
All the other RCA's and clones, were magnetic focus.
Maybe a focus control from a 7" Motorola or other would be close. Maybe one of the centering controls. The secret is insulating them from the chassis. :scratch2:

Nick, another possibility is the focus pot from one of the late 11940s RCA projection sets; a 15meg 4 watt pot. I may have one if you think you want to try it.

Any luck with Mark Oppat "King of Controls"?

http://oldradioparts.net/controls.html

.

John,

I need a 5-meg one, 15 would be more than the entire string. I suppose I could make some circuit changes, but for right now I'm going to try and put it back how it should be. I sent mark an email, let's see what he says. If I can't locate they right value, I'll have no choice but to pick either a 1 or 15 meg pot.

You could put some resistance in parallel with a 15M to get it down around 5M.

Nick,
What did the original pot look like? I've got some HV CTS pots here that are phenolic and about 2 1/2" in diameter.

Darryl

No idea, it didn't have a focus control. There was just a string of fixed resistors, so I'm tasked with installing one.

Nick
The black one measures 15M. The brown one says 6M but measures about 4M. The shafts are not connected to any terminal.

Darryl

Any way I could get you to send me the 4 meg one? No luck with Oppat yet.

I'll drop it in the mail today.

Gotta love VK, you guys are the shiz!

Darryl,

Got the control and cleaned it out with some deoxit, looks like it's gonna work! I'll have to play with the values in the string, but I won't be able to mess with it for the next couple weeks due to work. More when I get back to it, I owe you a sip of beer when we meet up again!