WHY so few "other brands' left out there?( Admiral, Sylvania , Philco, etc)

[andy]

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[Jon A.]

Originally Posted by andy

I think he just meant that it's impossible to do, unlike other brands which all use interchangeable CRTs (eg. you can put a Zenith CRT in a Sylvania TV, or a GE CRT in an RCA TV).

That's exactly what I meant. Kind of like the SG-613 transistors, it's OEM or no-go.

[dieseljeep]

Originally Posted by Jon A.

That's exactly what I meant. Kind of like the SG-613 transistors, it's OEM or no-go.

Several years back, I installed a Sylvania CRT in a Zenith set.
The picture is great, but the curvature of the CRT, is totally different. It doesn't fit the mask. There's a 3/4 inch gap, between the CRT and the cutout of the cabinet.
The end results! Two pieces of junk, made into one!
Same difference!

[rca2000]

But MOST of the time--one can do that--with NO problem. I have done it a lot, back in 'the day". An RCA tube (IIRC ) into a philco hybrid. Worked VERY well--NO gaps. A Zenith Chromacolor tube into an Admiral M25. Fit and worked VERY well.

If a tube fits right and is the same--even simliar electrically--it will normally work.. NOT on a junkatron though. They HAVE to be exact.

[Jon A.]

Yeah, it sucks about the curvature of some screens being different. Nevertheless, Sony aside, I never know which CRTs will fit which sets until they're actually in, so I keep any from older sets I scrap. Seems that RCA supplied CRTs to many TV manufacturers though.

Perhaps the mounting points alone were causing the problem with the fit? I'm unclear on this, but it sounds like the 3/4" gap was all the way around.

[dieseljeep]

Originally Posted by Jon A.

Yeah, it sucks about the curvature of some screens being different. Nevertheless, Sony aside, I never know which CRTs will fit which sets until they're actually in, so I keep any from older sets I scrap. Seems that RCA supplied CRTs to many TV manufacturers though.

Perhaps the mounting points alone were causing the problem with the fit? I'm unclear on this, but it sounds like the 3/4" gap was all the way around.

One the top and bottom, that gap was larger. The side, not so!
The manufacturers didn't have that many variations on the mounting configurations on CRT's made in the mid to late 70's.
A 23V or 25V, was about the same, no matter what firm built it. There was no problem making them fit.
Even if it had a tension band, it would fit.
No so, in the later CRT issues.

[andy]

Originally Posted by Jon A.

That's exactly what I meant. Kind of like the SG-613 transistors, it's OEM or no-go.

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[etype2]

Originally Posted by andy

I think he just meant that it's impossible to do, unlike other brands which all use interchangeable CRTs (eg. you can put a Zenith CRT in a Sylvania TV, or a GE CRT in an RCA TV).

It's a myth that Sony's don't require convergence. Trinitrons are less complicated to converge than a delta gun, but more complicated than a typical in-line gun.

I was thinking about the time when the Trinitron was first introduced. Decades later, other manufactures caught up to a certain degree but could never duplicate the Trinitron until Sony's Patent expired in 1996.

The Trinitron only requires 6 picture tube adjustment controls compared to 24 in the typical shadow mask of that period. The cathode are in one plane as opposed to different planes in the shadow mask system of that time period. The Trinitron uses no convergence yoke, instead 4 electrostatic convergence plates. Vertical mis convergence is impossible in a Trinitron tube, therefor vertical convergence control is not required. Only small horizontal corrections are needed left and right, also the vertical stripes make beam landing errors less sensitive to the Earths magnetic field.

[andy]

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[rca2000]

Don't forget the RCA -based tube with in-lne gun and the "magnetized tape" band over the end of the gun--for convergence. These usually required NO convergence adjustments--that tape did it all, set from the factory. Those tubes were not too bad , either. They hold up a LOT better than the JUNKatron tubes do !! JUNKatrons had an incredible picture...for a short time..before they died and could NOT be brought back. NOT really worth the premium Sony charged for them, often with a shitty, hot chassis to boot.

[sampson159]

i second that rca2000.those crts held up very well.a 23v and a standard 25 are the same.the reason the sylvania wouldnt fit right in the zenith was the corklike tape on the side of the crt mask.have to remove it so the crt will set in the mask perfectly.been there too many times not to know.a sylvania 25vdmp22 in a flat chassis zenith will make the ultimate set.the greatest chassis with the finest looking crt.done it once and had a mindblowing set that went with the ex.hope the other guy enjoyed it as much as i did.

[Jon A.]

I have a RCA inline CRT with the magnetized tape on it, a 19VLNP22. Worked awesome when pulled.

Originally Posted by sampson159

a 23v and a standard 25 are the same.the reason the sylvania wouldnt fit right in the zenith was the corklike tape on the side of the crt mask.have to remove it so the crt will set in the mask perfectly.been there too many times not to know.

Good to know. Those 70s Sylvania consoles are among my faves.

[dieseljeep]

Originally Posted by rca2000

Don't forget the RCA -based tube with in-lne gun and the "magnetized tape" band over the end of the gun--for convergence. These usually required NO convergence adjustments--that tape did it all, set from the factory. Those tubes were not too bad , either. They hold up a LOT better than the JUNKatron tubes do !! JUNKatrons had an incredible picture...for a short time..before they died and could NOT be brought back. NOT really worth the premium Sony charged for them, often with a shitty, hot chassis to boot.

Sony's picture quality sold the set.
I'm well aware of the CRT's in certain models, that didn't stand up well!
I only replaced CRT's in two Sony sets. One from a junk set and one purchased as a new tube. That was the mid-70's 19" set. That CRT was made in California. I also saw two heavy-beast 26" consoles, where the CRT's were really sick.
I have several Sony's in my possession and all but two have perfect pictures.

[etype2]

I concede that there may have been a few inline sets in the 70's, but I don't recall inline sets making big news other then Sony until the 80's and 90's.

For those who denigrate Sony sets, "crappy and junkatrons" I offer a few more screenshots in addition to the KV 1722 posted above.

KV 1220U from 1969





KV 9000U from 1970



These two sets are part of my collection 45 and 44 years old and still going strong.

[andy]

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