When did bonded yokes become the norm?

[zenith2134]

I was looking through some SAMS photofacts and in the folder for my RCA 'KCS' chassis b/w set there is an RCA bulletin re: bonded yokes. They were cautioning about handling the crt with care, watching out for HV, etc... and one of the warnings said that the servicer shall never attempt to separate the bonded yoke which is available 'on some cathode-ray tubes' .

This was from '79 .... but I thought the integrated deflection yokes were more common later on, say, in the early 90s sets. Anyone care to discuss this some?

[andy]

...

[sampson159]

early 74-75 rca portables had inlines with bonded yokes.removed them with an exacto knife and alot of care.dave was the master.he could do it like clockwork.sylvania had a really nice removable yoke and convergence assembly.my shop days were over by 1989 so after that,i am a little lost.here in south columbus,we saw mostly low level sets.saw very few bad inline crts on those rcas though.dont remember why were were removing them.

[kx250rider]

They seemed to be most popular in the early 90s, and then seemed to disappear by the early 2000s to the end of CRTs. Toshibas were almost all bonded yoke, but as said above, you can CAREFULLY get them off. I used to have to cut them off to reset purity in TVs which were bumped or dropped, and caused slight shadow mask damage. 85% success.

Charles

[jstout66]

I remember as a kid working in my Uncles repair shop, a few 1977/1978 era Magnavox portables had them, and my Uncle commenting about it. I think those were the first ones he saw.. I remember the set (17") having an inline tube, and a lousy picture, and it was only 3 years old at that time.

[Findm-Keepm]

Originally Posted by jstout66

I remember as a kid working in my Uncles repair shop, a few 1977/1978 era Magnavox portables had them, and my Uncle commenting about it. I think those were the first ones he saw.. I remember the set (17") having an inline tube, and a lousy picture, and it was only 3 years old at that time.

Yes, definitely Magnavox - my Dad was fixing one of those 19" Magnavox Table sets that looked like a consolette for another TV shop. He slipped while working on it, and got to replace/buy his first bonded yoke CRT. This was in 1979.

The first XL100 set I ever scrapped was a CTC72 with a bonded yoke - it was also a 19". I recall it was just over a year old, low hours, and had a HV problem that arced and cut the neck cleanly. Instant supply of good MAD/MAG/MAL/MAH modules!

Cheers,

[radiotvnut]

I remember working on one Magnavox, circa '74-'75 19" set that had an inline tube with a bonded yoke. I don't remember the chassis number; but, it was the chassis that was around just before the vertical T991 19" chassis came along. The T991 was one of the ones that used a 4 lead safety cap that was very prone to shorting and this set also used a bonded yoke CRT.

I've seen some other cheap imported sets of the '70's and '80's that had a label on the CRT that warned that the yoke and convergence assembly was bonded to the CRT and warned the servicer not to attempt removal. However, on these very sets, I have loosened the clamps and the yoke and convergence assembly came off as easy as any other non bonded yoke.

Bonded yoke tubes are nice in the fact that one does not have to fool with purity and convergence; but, they are not so nice if the yoke becomes defective and the whole CRT has to be replaced.

[dieseljeep]

Those 4 lead caps were an oil cap. I took a hammer to the white ones used in a Zenith and the inside was greasy and they had a rubber band holding something together. Magnavox used the same vendor even after the word got out about those caps. I always considered Magnavox as an overpriced "cheapy" product.

[marty59]

Quote: I always considered Magnavox as an overpriced "cheapy" product.

They became the butt of many jokes in the trade..and took an unfortunate slide downhill in the seventies..prior to that it was 180 degrees different.
And those later models with the faux plastic cabinets and "bonded" yoke tubes..yuk!

In fact, how it became to be I'm not sure but Magnavox during the seventies did aquire Ampeg and made some killer gear in those times. I've worked on numerious pieces from that timeframe and the artwork on the PC boards and the pastel colored wiring just "screamed" Magnavox!
Ampeg really became a major player with their SVT series of amps using 7027's and those big bass heads with 6550's.

Magnavox as an overpriced "cheapy" product? How sad it became to be. The Philips/NAP aquisition was a good thing.