Quote:
Originally Posted by mattdavala
I'm sure most TV's did have static focus although my 21 inch Majestic console has electrostatic focus and it is from 1955. Its CRT is a non standard replacement, 21EP4B. Its on its way out. ..... Brightness almost full, slight blooming, retrace lines on dark scenes.
If I never plan to sell my TV, spending 250 dollars for a CRT rebuild might be worth it. The TV is a joy to watch.
Best regards,
Matt Davala
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What do you call 'static focus'? According to my RCA RC-29 Tube Manual
(1973), all B&W CRTs listed have either Electrostatic focus (a grid that
you connect to the correct potential, sometimes with taps, sometimes
with a potentiometer) or Magnetic focus (a focus coil). The only two
tubes that list a different focusing method (Automatic) are two test
tubes (8XP4 and 8YP4).
My two TVs, from 1956 and 1960, use electrostatic focus tubes
(21ALP4A, 90 deg. and 21DEP4, 110 deg.).
Regards.