As per the 1982 Amateur Radio Handbook, ECC83 (and ECC82) are double
triodes. Type 83 is described as a half wave rectifier in the 1951
edition. None of the 12* are listed in the '51 book though similar
numbers indicate double diodes and triodes as do base descriptions
in the 1982 book but I cannot come up with more precise info.
bs
On Fri, 29 Aug 2008, Tony Duell wrote:
Chuck>
Were these the special "space charge" tubes? e.g. 12J8, 12U7,
Chuck> 12DK7, 12DL8, 12CX6, 12DE8, 12CN5, 12BL6, 12DS7, 12AC6, 12AD6,
Chuck> 12AE6, 12AE7, 12AF6, 12AJ6 or 12AL8 (I've probably left out a
Chuck> few)?
I don't recognize the term "space charge". They were tubes explicitly
specified in the data sheet for operation with 12 volt anode voltage.
Almost certainly they were Philips -- EFnn and ECHnn for suitable
integer nn... (I did that project in Holland.)
I think nn=83 :-). I am really digging into the depths of my memory, but
I seem to remember the ECH83 (triode hexode frequency changer) and EBF83
(double diode and pentode). Maybe at least one other type too.
-tony