29 Feb
2012
29 Feb
'12
12:55 p.m.
I'm not having much luck finding examples of
actual models, and I
don't know about RCA specifically, but TMU there were theatre or
large-screen projection TVs made with Kerr cells (for light
modulation) and rotating mirrors (scanning) for display of the
standard TV signal around that era. I thought Scott made a home TV of
this form (40s). As such, there were mechanical-scan systems aside
We had back-projection home TVs over here -- White-Ibbotson was the best
known. But they used a small convntional CRT (2" screen) with a highr
than normal EHT (25kV or so) in a Schmidt-type optical assembly. No
mechanical scanning.
Did you have 'mirror in the lid' TVs in the States? Due to the small
defleciton angle, the CRTs in early (1930's) TVs wrre very long from base
to screen. Some mnufactuered stood them vertically with the screen on top
and had a front-silvered mirror in a hinged lid on top of the cabinet.
For viewing you lifted the lid to the 45 degree position and viewed the
refleciton of the screen in the mirror.
(Yes it would be back-to-front compared to what was actualyl on the
screen, but having one of the defleciton coils revesed mant the picutre
you actually saw was the right way round)
Again fully electronic scanning.
-tony