07-13-2023, 04:13 PM
Hi Dale,
Attached is the Tung Sol Spec Sheet I described. Like RCA, they do not list different specs for 42 or 2A5 (in RCA RC12) or between 42, 2A5 or 6F6 (Tung Sol), other than heater voltage / current. There are 2 different listings in the Tung Sol document for triode Push Pull operation. "Typical" states 6K Ohm for triode connected Push Pull, there is a listing for "cathode bias" showing 10K plate resistance for AB2 Push Pull operation.
However, this is academic, as the Philco docs that Ron has stated 6K Ohm Plate resistance. Of course, this info is all lightyears before computers, so either there are mistakes, spec differences between manufacturers or whatever.
Attached is the Tung Sol Spec Sheet I described. Like RCA, they do not list different specs for 42 or 2A5 (in RCA RC12) or between 42, 2A5 or 6F6 (Tung Sol), other than heater voltage / current. There are 2 different listings in the Tung Sol document for triode Push Pull operation. "Typical" states 6K Ohm for triode connected Push Pull, there is a listing for "cathode bias" showing 10K plate resistance for AB2 Push Pull operation.
However, this is academic, as the Philco docs that Ron has stated 6K Ohm Plate resistance. Of course, this info is all lightyears before computers, so either there are mistakes, spec differences between manufacturers or whatever.
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Best Regards,
MrFixr55