Conrac CYA 17" Color Monitor

[dieseljeep]

Originally Posted by Electronic M

I wonder if this was the same tube used in the consumer 1958 model Westinghouse sets? I thought that was a 22" though. If they were different I wonder if our rectangular color CRT came out first?

Those CRT's were made by CBS-Hytron. The earlier 19" rounds that Motorola, CBS and Raytheon used, were made by them, as well.
I guess, you could consider the 22" first, but it was a flop, where the early 60's Toshiba, must have been considered a success.
I'm one of the sorriest people on earth, that I dumped the Toshiba-built Sears set, years ago. I haven't seen one before, or since.

[Electronic M]

We all let go of something, and come regret it at least once...Occupational hazard of being a collector.

[jr_tech]

Originally Posted by Electronic M

I wonder if this was the same tube used in the consumer 1958 model Westinghouse sets? I thought that was a 22" though. If they were different I wonder if our rectangular color CRT came out first?

The Photofact (357-12) for the Westinghouse 22" rectangular sets is dated 5-57. By 1958 Westinghouse had ditched the 22EP22 and replaced it with a 21CYP22.
The US made tubes rectangular likely were first:
http://www.earlytelevision.org/22_inch_color_tubes.html

jr

[drussell]

Originally Posted by reeferman

Paraphrasing the book (cause I couldn't lift it) "In 1958 the first rectangular 17" color CRT, 70 degree was manufactured entirely of Japanese parts".

Originally Posted by Electronic M

I wonder if this was the same tube used in the consumer 1958 model Westinghouse sets? I thought that was a 22" though. If they were different I wonder if our rectangular color CRT came out first?

According to my copy of Peter A. Keller's 1991 book "The Cathode-Ray Tube: Technology, History, and Applications" (an interesting book, BTW) section 6.10 "Rectangular Shadow-Mask Color Tubes" on page 184-5:

The first commercially available rectangular color tube was the 22-inch, all-glass 22EP22 (figure 6.22) developed by Westinghouse Electric Company in their Elmira, New York plant (1956). A 24-hour-long pump cycle combined with a high-temperature bake (400 degrees) resulted in a very good vacuum and long life. The 22EP22 was used in a television receiver manufactured by Westinghouse, but economics doomed it after only one year of limited production. The long pump cycle limited production and Westinghouse was unable to compete with RCA who was selling receivers at a loss in order to develop the market.

He then goes on to talk about the 25AP22 with no mention of the years in between or any of the Japanese tubes, unfortunately:

It remained for RCA to produce the 25-inch rectangular tube in 1964 before the rectangular screen format spread through the color television market as it had the black and white market 15 years earlier. Rectangular color tubes made their successful commercial debut with RCA's 25-inch, 90-degree deflection 25AP22.* Rectangular tubes had long been the norm for black and white television, but the less-critical round tube had served the color television industry through its comparatively long incubation period and by the early 1960s the process for mass-production were established and well understood. The 25AP22 had a living room-sized screen while being over four inches shorter than the round 21-inch series of tubes. Several new features were introduced in this tube, including a flatter screen, an aluminum foil electron shield between the edges of the shadow mask and the bulb to prevent scattered electrons from reaching the screen and degrading contrast, and a more compact electron gun. The latter allowed the use of a smaller diameter neck (1-7/16-inch (36 mm) versus the previous two-inch diameter) which reduced the deflection yoke power and size requirements, and improved convergence by placing the electron beams closer together. Also new to color picture tubes was the hard-pin stem which eliminated the need for a separate base by employing short, stiff, feed-though wires on the stem as pins to mate with a socket -- a trend initiated in the late 1950s for monochrome picture tubes.

With the 25AP22 and the soon-to-follow 25BP22, 19EXP22 and 19EYP22 by RCA in 1965,** the floodgates opened for new rectangular color picture tubes by all of the major U.S. manufacturers. Up to the late 1960s all tubes utilized the early dot-triad screen with the three electron guns arranged in a triangular fashion about the neck axis in what was termed a delta-gun configuration. (Sections 6.12 and 6.13 discuss the further major evolution of the shadow mask color picture tube in the Trinitron and the slot mask / in-line tubes.)

In the late 1960s picture tube faceplates became somewhat squarer and tube designations changed as a result of a Federal Trade Commission ruling requiring actual viewable screen dimensions to be advertised rather than overall glass dimensions as previously used.*** The letter "V" was added after the screen size in EIA tube registrations to indicate viewable inches, e.g., the Rauland 19VMJP22. At that time tube type numbers had become quite lengthy.

* Morrell, A.M. and Hardy, A.E. "Development of the RCA 25-inch 90-degree Rectangular Color Picture Tube," IEEE Trans Bcst TV Recvrs, BTR 10, pp. 15-22, 1964.
** Morrell, A.M. "Development of the RCA family of 90-degree Rectangular Color Picture Tubes," IEEE Trans Bcst TV Recvrs, BTR 11, pp. 90-95, 1965.
*** Federal Trade Commission Trade Regulation Rule "Deceptive Advertising As to Sizes of Viewable Pictures Shown by Television Receiving Sets," pp. 1-4, effective July 1, 1966.

[andy]

...

[grimer]

I have a Conrac monitor,it has the rectangular Hitachi tube
http://i242.photobucket.com/albums/f...ps5f6af02f.jpg

[Phototone]

Originally Posted by andy

Here are some pictures of my Sears/Toshiba. The cabinet was completely falling apart. The sides and top were made of a single piece of very thin plywood that was bent at the corners. I have replaced the sides and top, and I just need to finish it so I can put the CRT back in and restore the chassis. It has a lot of bad caps in it, but the CRT tests good.

I remember seeing one of those at our local Sears store. I wanted one, but my dad wasn't ready to spring for a color set yet. I remember one time, the picture was upside down, as an attention getter. They (I think) turned the yoke upside down?

[Electronic M]

All it takes to flip the picture up side down on any set is to reverse the vertical yoke leads...On most large neck color sets it was especially easy since the leads individually plugged in to the yoke.

[wa2ise]

Wonder if the model number "CYA" stood for "cover your ass" Intended to be used say at the transmitter site, so the engineers there could verify that the video signal was good, to CYA...