12 Aug
2014
12 Aug
'14
3:19 p.m.
Which reminds me--there was a gas-filled half-wave
rectifier called the
0Y3 (it was distinguished by an extra "starter" electrode). The odd
thing is that 0Y3 is also the part number for a German germanium diode.
I beleive, strictly, the German diode is an OY3, not a 0Y3. Old European
semiconductors used the smae letters as the vlave code. The 'O' (not
zero) for the ehater voltage meant semicondcutor device. A is a signal
diode (so OA81, etc), C is a triode -> transsitor (so OC71 germanium
transsitor) and Y is a power diode/rectifier.
Actually, those letters -- almost -- carry on to today. The first letter
was reassigned ot be A for germanium and B for silicon. So an AA119 is a
germanium signal diode. C is still trasnistor (think of AC128, a
germanium transistor and BC108, a silicon transistor). D, originally
power triode is sometimes used for power transsitor (AD161, BD131, etc)
.F, origianlyl a pentode, then became an RF transistor (which makes
sense, both are high frequency amplfiiers). So AF117, BF259, etc.
The name comes
from the fact that hte beam forming plates etc supress
the econdary emision from the anode, so the IA-VA curve doe not have
the negative resistanve part that is forund in the curve of a plain
tetrode.
Never heard the term "kinkless" before. A common source of confusion was calling these "pentodes", which was a
very different thing, as, say
the EL34
_Very_ differnet? Yes, the electrode structure is different, but in some
cases you can directly repalce one with the other. The characteristics
can be vey similar
-tony