In article ,
robert casey wrote:

But back in the early
70's, table radios made the transision from the "All American 5ive" tube
circuit to a solid state circuit that used a high voltage bipolar
transistor and output transformer for the audio output.


I'm not sure exactly when this transition was made, but I do know that
it occurred sometime well before the "early 70's", I would say that the
transition occurred in the mid 60's, I know from personal experience
that these radios were already in production by late 66, when they first
went into production I don't know.


I was thinking of the SS radios that were "hot chassis". The audio
output transistor had about 100V B+ on it. Before these, there were
some SS radios that had small power transformers and were essentially
portable circuits inserted inside a table radio cabinet. But it's the
hot chassis high voltage transistors that ran in class A "single ended"
I was thinking of.

Yes, it was the hot chassis sets with 100V B+, or greater, on the output
transistor that I was speaking of. IIRC the RF, IF, and low level audio
stages in these radios operated at a low, more normal transistor,
voltage obtained from the emitter circuit of the output transistor. The
B+ for the output transistor came from a rectifier connected directly to
the power line as in an AA5.


Regards,

John Byrns

--
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