Quote:
Originally Posted by ohohyodafarted
Tom,
I have to agree 100% with your thesis about the safety of the FB vs the FJ tube. Upon thinking about the reasoning for the manufacturers to transition from the air gap to the bonded resin face plate, I think this may have been more a mater of not having to clean the dirty inner glass surfaces of the FB type, and less a mater of safety.
As a result, especially in homes of the 60's when cigarette smoking was still commonplace, that polluted air was drawn into that air gap and could create a film of smoke on the glass surfaces in the air gap. <snip>
But I do remember at least one service tech who asked if mom and dad wanted him to clean the glass (on a B&W set). And when he showed them how much smoke film was on the face of the crt and the inside of the safety glass, mom and dad were astonished. And the picture was visibly much sharper and brighter after the cleaning.
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Oh, the memories! The first TV I trashpicked and repaired (a circa 1959 blond Zenith 16C21 I found in the summer of 1980, I was sixteen) had a weak 1B3 (I was beaming with pride to have recognized the blooming failure and knowing how to fix it immediately!), only to find the picture had a deep brown cast. I removed the safety glass, and used an hour, a whole roll of paper towels, and a lot of window cleaner to get it all done.
Had a lot of fun with that set. It was extraordinarily sensitive on lowband VHF, and made great use of it to chase TV DX by Sporadic-E skip over the next three summers (longest catch: KREM Spokane, 1702 miles from Detroit's East Side).
During the third summer, the abused tuner was getting glitchy. I cleaned the tuner contacts, but when I fired it back up, the performance was only ordinary (sigh).
My guess is that the dirty tuner had been allowing some regeneration to occur, reducing bandwidth and increasing gain.