21 Apr
2005
21 Apr
'05
5:52 p.m.
Certainly, multifunction tubes were around - the first
ones were the dual
diodes and rectifiers of the 1920s, then later twin triodes, extra diodes,
and yes, to the ultimate Compactrons.
The most complex common multi-section valve in the UK (i.e. with the most
sections), is the triple diode triode. It came with a variety of heater
ratings -- the EABC80 (6.3V heater), UABC80 (100mA series string heater,
by far the most common version) and the oddball PABC80 (300mA series
string heater). It turned up in numerous AM/FM radios in the 1960s, where
it was used for the AM detector (1 diode), FM detector (the other 2
diodes) and audio ampifier (triode). It has a B9A (9 pin miniature) base,
so there must be some commoning of electrodes going on, probably the
cathodes.
-tony