25 Nov
2011
25 Nov
'11
2:16 p.m.
On 25 Nov 2011 at 20:59, Tony Duell wrote:
There's the dynatron oscilalator (nothign to do
with the UK radio
company of that name AFAIK) which depends on the negative resistance
part of the Ia .vs. Va curve for a normal tetrode. The beam tetrode
was sometimes called a 'kinkles tetrode' over here, because it doesn't
have this dip in the chracteristic curve, and the 'KT' in valve
numebrs like KT66 and KT88 stands for 'Kinklrss Tetrode'.Needless to
say those can't be used as dynstron oscillators.
Found a Wiki reference to "Barkhausen-Kurz" tube:
http://en.wikipedia.org/wiki/Barkhausen-Kurz_tube
and found a mention of same in an old (pre-war) electronics text.
Apparently if you add some tuned circuits to a Barkhausen oscillator,
it's called a "Gill-Morell" oscillator. Same Barkhausen as the
Barkhausen effect, however.
Said text also mentioned that the best oscillation was obtained from
triodes with circular (versus oval or rectangular) elements, which
figures. Even has a practical circuit using type 76 triodes.
--Chuck