23 Apr
2006
23 Apr
'06
2:05 p.m.
was replaced by the daylight-view CRT by the end of
the war, and projection
CRTs were available (Skiatron?), reliable projection TV sets made there
appearance in the UK shortly after WW2 (using a 2.5" tube with a 25KV EHT,
and a very clever optical unit).
From what I've read, that optical unit was
basically a schmidt telescope
in reverse, with a 45-degree mirror so it could be
bent to fit in the
cabinet....
I've also hrarf plenty of bad things about them from engineers of the day
who said they were a right pain to set up properly, and that although
there were protections circuits, it was not at all uncommong for a line
to be burnt in the CRT phosphor if one of the deflection generators
failed.
Somewhere I've got some service information on the White-Ibbotson (?spel)
set. Setting up that optical unit seems to be somewhat 'interesting' to
say the least...
-tony