Question for Don Lindsly ......

[Kamakiri]

Hi Don,

Saw that you're an ex-Philco employee, so maybe you'd know this

My RCA CT-100 was purchased new by the Philco corporation as a research and test model in their development of color TV. By any chance do you know any of the history on my set?

Thanks!

[bgadow]

There is a real wealth of knowledge on here...I have been waiting to find out what Don can tell us about Philco! Inquiring minds & all that...

[Don Lindsly]

Sorry I don't have any first hand knowledge of the RCA CT100 history. I do remember that the CT100 was available in 1953. Poor sales were likey the result of limited color programming and an overly complex design. Philco's Color TV development started well before the CT100 was available so I doubt the engineers learned much.

Philco bought loads of competitive TVs for evaulation and to check for patent infringements. There were ongoing patent conflicts over color in the early 50s between Philco and RCA. You will note some subtle circuit similarities between the RCA and the original 1956 Philco TV123. That was many years before RCA was supplying chassis to everyone else.

Philco was involved in the NTSC standards setting and well along the way with the single gun color (Apple) tube. When Ford took control, it was decided not to make the investment to finish the R&D and put it into production so the technology was sold to Sony.

I recall the Philadelphia RCA distributor had a promotion sometime in 1955-56 providing a free CT100 to service dealers who bought a load (500-1000) of receiving tubes. It put a lot of color sets out and gave dealers some experience. It also cleared out the warehouse to make room for the 21 inch CT660 series.

[Pete Deksnis]

This bit is based upon both fact and recollection and therefore is subject to updating.

Sylvania supplied a pin-for-pin equivalent of the RCA 15GP22 to Philco. The 15GP22’s were Sylvania branded and came from the large Sylvania tube manufacturing plant in Seneca Falls, New York, which Phillips closed around 1985 after buying the GTE/Sylvania assets earlier in the decade.

Perhaps because Philco was really pissed at RCA for taking the lion’s share of credit for the 1953 NTSC color system in the eye of the public, Philco seemed to avoid RCA 15GP22’s. Period documentation strongly suggests that Philco contributed the quadrature method of combining the I and Q components of the color broadcast signal. Around 1965 I spoke with an engineer who had worked for Philco. The impression I took away from that discussion supports the notion of bitterness by Philco toward RCA over the public’s perceived monotheistic development of color television by RCA.

One of the CT-100’s shown operating on my site has a NOS Sylvania 15GP22 that had been originally sold/shipped to Philco. Here’s a link to an operating Sylvania 15GP22 in a CT-100:

http://home.att.net/~pldexnis/HoF/AndyLee.html

More in keeping with the original question though, according to Chuck Azzalina, the 1953 Philco 15-inch color prototype he restored, and developed a schematic for, was NOT based upon the RCA developmental Model 5, the forerunner of the CT-100.

Quote from Don: "You will note some subtle circuit similarities between the RCA and the original 1956 Philco TV123."

My current restoration project is one of the four known 21AXP22-based 1956 Philco 22D5102 color sets. Much to my surprise after digesting the Philco prototype information from Chuck, the TV-123 (chassis designation of the 22D5102) circuitry mimics the CTC2 in the area of chroma processing, particularly the control-circuit for the chroma reference oscillator. The vertical centering circuit in the Philco is also similar to that in the CTC2 through CTC4. That didn’t change until the RCA CTC5.

[Don Lindsly]

Thanks for the interesting follow on.

Sylvania made a lot of tubes for Philco, CRT and othewise. Regardless of the brand name, if the tube is coded 312, then it was made by Sylvania. If it's coded 260, it is a Philco.

I worked on a lot of those Philco TV123 chassis. Many of them ended up in executive's and dealer's homes and a considerable number in consumer's hands. I had one myself for a few years and eventually sold it to my boss at Philco.

Philco provided a massive modification kit for that set. It called for a sub-chassis to enable 2 5U4s to replace the 5V3, totalling 3 LV rectifiers. It also included an improved flyback and high voltage rectifier circuit, a few resistors and capacitors, horizontal output tube and other parts. It greatly improved reliability.

There was also a cable kit, PN# 425-0004-1, to facilitate service. That included yoke, high voltage, CRT and convergence cable extensions. I still have one of those in the box, but I doubt that it's complete. I also have what's left of a factory test set up. It was a huge wooden roll around rack that housed the CRT and allowed room to work on the chassis. I have since cut it down and use it for a radial arm saw.

That TV will put out a nice picture. It will not overload the chroma saturation like an RCA or GE, but will have enough.

Don

[ChuckA]

One other item I found in the Apple documents on the Philco TV-123 sets, was they were designing the TV-121 in late 1954, and the TV-122 in early 1955. The 122 appears to be the prototype for the 123, the circuitry is virtually identical and it used some proprietary tubes in the LV power supply and HV circuits. From the documents they never built a model of the 122, but may have built a 121.

The 121 has more in common with the 123 than the earlier prototype of 1953, in fact comparing the schematics it looks like Philco discarded pretty much everything in the prototype when they started the TV-121.

And Don you are correct, after restoration and alignment the picture quality of the TV-123 is great.

Chuck

[Don Lindsly]

Chuck:

I don't recall anything earlier than the TV123 out of the lab into serious production. I never saw a Philco 15 inch in use. One chassis version may have been to drive the Apple tube since it required some different circuitry. A few got into engineer's homes for test, but programming was limited before 1957 when NBC went all color.

Do you have a source for the Apple documents yoreference? I would find them most interesting.

Don

Product prototypes were sometimes sold to employees on a limited basis.

[Dave A]

Don,

The TV123 documents came from one Bert Soltoff, a former Philco engineer, later working for RCA on the lunar field-sequential cameras for the early moon landings. Does his name ring a bell?

I picked up a TV123 from him and he was kind enough to give me all of his documents which I gave to Chuck for research. We are indebted to him for saving them.

Chuck's description of the sequence of events is accurate given the documents and schematics...some of which are hand-drawn. The whole collection is clearly an attempt at a conventional tri-color 21" set far different than Philco's attempt a 15" set. It is doubtful that Philco ever got beyond prototypes for the TV121 and TV122.

Even more interesting is your description of many TV123 sets being produced. Urban legend around here in Philadelphia is that about 500 TV123 sets were produced with CRT's supplied by RCA. The legend continues that the CRT's were less than good quality with a spectacular failure rate. We cannot figure out how only 4 sets remain...and one spare parts chassis.

Chuck has posted some of the Apple information from the documents that exist. You can see them at;

http://www.myvintagetv.com/philco_apple_tube.htm

Look there for the file about the Apple test benches. Could it be what you have? They were given women's names as I remember.

Dave A

[Pete Deksnis]

Originally Posted by Dave A

Urban legend around here in Philadelphia is that about 500 TV123 sets were produced with CRT's supplied by RCA.

Just checked the 21AXP22 in my TV123. It's the original CRT shipped with the set (TV123 chassis s/n 356). The CRT has a date code from early 1956, as do most of the tubes in the set, but the manufacturer's code is 312 — Sylvania, based on Don's previous post.


As noted on Chuck's site, the four known TV123 serial numbers range from 299 to 356; odd that all these serial numbers fall within a cluster that encompasses just ten percent of the 500 or so believed to be manufactured, suggesting either a quirk of statistics or perhaps that even fewer than 500 were produced?.

[Don Lindsly]

I did not know Bert Soltoff. Great historical information on that site.

I would suspect that more than 500 TV123s were manufactured. I worked on at least a couple dozen. There were loads of them throughout the Philadelphia area. Maybe it seemed like more because I saw them so often.

When Philco finally came out with the modification kit mentioned earlier, reliability improved considerably. The service dealer was paid $20 to install it as I recall. That was ample for the time. It was easy to obtain the kit, but the dealer didn't get paid until the paperwork was in. I installed a lot of them, but most TV123s I hear of today do not have the kit.

The manufacturer's OEM codes were on tubes and parts, usually preceeding the date code. Sylvania was 312, RCA was 274, GE was 188, Philco was 260, Automatic Coil was 119 and so on. You may see an IF coil with Philco and a part number stamped on it, but you will also see something like 119735 meaning Automatic Coil, 1957, 35th week. As the years have passed it is possible to be off by a decade so it requires some guess work. Many parts went to four number date codes to avoid confusion and warranty fraud.

The marking color also indicated whether the tube was OEM or replacement. White, yellow and later blue were OEM. Red was replacement. If you see a Philco TV with a bunch of red tubes, they're replacements, not originals.

Don

[John Folsom]

Don,

Is there a list published somewhere of the manufactures codes?

[Tim]

John:

These seem like the standard EIA Manufacturers codes. Here is a list:

http://www.triodeel.com/eiacode.htm

[Pete Deksnis]

Original written by Don Lindsly: I worked on a lot of those Philco TV123 chassis. Many of them ended up in executive's and dealer's homes.... Philco provided a massive modification kit for that set. It called for a sub-chassis to enable 2 5U4s to replace the 5V3, totalling 3 LV rectifiers.

Re the 'massive' retrofit kit, which included a subchassis that replaced a 5V3. I know the reason for that part of the kit. The original rectifier sockets were on the power transformer. According to the original owner, a Philco dealer in Egg Harbor City, NJ, the 5V3 and 5U4 got so hot the solder in the pins would melt. He mimicked the kit with power-cable wire and old sockets to move one rectifier off the transformer. This ‘remote’ socket with its 5U4 was still inside the cabinet when I got the set.

[Don Lindsly]

John:

Tim answered with a list I have never seen before. Thanks Tim.

Pete:

The official reason for the two 5U4s replacing the 5V3 was reliability. The 5V3s seemed to last about four or five months. I never replaced a 5U4 in a modified set. The 5V3 did run extermely hot so it's possible that it melted solder joints. That would take 600 degrees so it may have just crystalized them with the same result.

The kit had loads of other stuff in it. A healthier horizontal output tube, flyback and high voltage rectifier circuit were all intended to improved reliability. For the most part it worked as designed.

Don

[Chad Hauris]

As far as I know a 5V3 is just a 5U4 with a 4-pin base...it probably really needed 2 5V3's initially.

Correction...maybe it is a 5Z3 that is the same as a 5U4, I know there is a 4-pin rectifier tube the same internally as a 5U4 but maybe I should have double checked the tube manual before I commented.