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-   -   First flat-faced CRT? (http://www.videokarma.org/showthread.php?t=262994)

zenith2134 11-09-2014 07:13 PM

First flat-faced CRT?
 
Who came out with the first flat face CRT? I'm not talking about the Trinitron, which as we all know is flat from top to bottom technically.
I seem to recall an 80s Zenith with a flat CRT, way before they became a norm in the end-of-CRT era.
It had to be an all-solid state TV/monitor I assume. Were any monochrome CRTs with a flat face produced?:scratch2:

jr_tech 11-09-2014 07:19 PM

The first that I remember seeing was a Toshiba 20 inch "flat square" (FST) model that they wanted an arm and a leg for... early 80s, seemed to be a minor breakthrough at the time.
jr

Geoff Bourquin 11-09-2014 07:32 PM

Zenith "Flat Tension Mask" is the first flat screen tube I can think of. As far as I know it only found its way into computer monitors. Not sure of the date, but IIRC it was mid-80s.

jr_tech 11-09-2014 08:06 PM

A very expensive, very rugged high resolution flat face FTM Military Avionics display (T-8650) was produced by Tektronix as early as 1983. Big $$$$$ for a 5" jug!

jr

Username1 11-09-2014 08:36 PM

I thought it was RCA when they came out with that 26 or 27" mostly flat face tube....
It was really square too.... Is that the one where if the shadow mask got hot they were
warping.... Wasn't that early 80's....?

andy 11-10-2014 01:44 AM

...

zenith2134 11-10-2014 07:27 AM

hey Andy, I forgot about that Zenith monitor. Probably what I was thinking of. I didn't know that the cheap flat CRTs had a curved inner surface..I like finding out small details like that..Nowhere else on the internet can someone really find out all this lost knowledge on old TV technology!
Username1, it is interesting what you said about the shadow mask warping on some of them..I actually made a thread here once asking about just how high the temperature of the mask can get in a color TV.
jr_tech-I'm not surprised that Tektronix had a hi-rez flat tube..just about all of their stuff was high quality and very expensive!! Wonder how many of these still exist?
Geoff Bourqin, would you say that the Zenith monitor which Andy pointed out uses that FTM tube?

Electronic M 11-10-2014 12:48 PM

I seem to recall seeing a picture of a pre-war CBS field sequential prototype with a developmental rectangular CRT that appeared to have a flat face.

rpm1200 11-13-2014 09:54 AM

Quote:

Originally Posted by Username1 (Post 3119176)
I thought it was RCA when they came out with that 26 or 27" mostly flat face tube....
It was really square too.... Is that the one where if the shadow mask got hot they were
warping.... Wasn't that early 80's....?

I think that was around '87... the second gen Dimensia TV being one example. NEC also had a 27-inch "nearly flat" tube around then. Then in the early 90s Panasonic came out with the "Gaoo Superflat" series, same idea.

Some of the small portable color TVs had tubes very close to flat and square.

I used to have one of those Zenith Data Systems monitors. The screen was ruler-flat, but the picture appeared to bow in very subtly at the middle. I was told that was an optical illusion due to being used to curved-screen monitors, but did not observe that effect with later flat CRT computer monitors (like the Sony Trinitron ones that came out around 2000).

JBL_1 11-28-2014 03:56 PM

Quote:

Originally Posted by rpm1200 (Post 3119400)
I think that was around '87... the second gen Dimensia TV being one example.

I haven't thought about that set for years. Was just coming out when I joined RCA in 1984. Used the CTC-133 chassis. Wasn't completely flat, had two bumps in the middle. Remember the guy that made the blister blaster circuit that was tacked in at the last minute to pull down the contrast when bright spots appears for a long period of time...

colorfixer 11-29-2014 02:02 AM

The 15GP22 had a flat phosphor plate...albeit in a curved envelope ;)

andy 11-29-2014 10:12 AM

...

Alastair E 11-29-2014 03:36 PM

In the very late 60's, early 70's the Russian Co, Mashpriborintorg (sp) released to the UK market a 6" B/W portable under the Rigonda name that had a flat faced CRT....
The set was all transistorised--with weird Russian transistors, very well constructed for what they were, and had an EHT doubler, run from this odd sealed flyback transformer.
The sets had issues with flyback transformers and the field-timebase stages.

These sets were sorta given away with tokens from Corn-Flakes as I recall, and when working correctly gave a fairly decent picture, although appeared to be dished inwards--probably as we were all used to seeing pictures on goldfish bowls at the time!

Here's one Ive found on ebay--Nothing to do with me BTW.....

http://www.ebay.co.uk/itm/Vintage-Ri...item19f786249b


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