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Old 20th Oct 2019, 7:07 pm   #33
m0cemdave
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Join Date: Feb 2009
Location: Bletchley, Buckinghamshire, UK.
Posts: 1,205
Default Re: Single-ended Transistor amps.

Quote:
Originally Posted by G6Tanuki View Post
I've also found a couple of AUY10 - which was one of the first early-60s TO3 Germanium power transistors that worked satisfactorily up to 10MHz or so (I believe it was originally designed for use as a ferrite-core-driver for computer memories). meaning I'm now wondering if the output transformer for any "single-ended transistor amp" should also include a tap to let me use it as an AM modulator?
Probably a subject for another thread, but I think the AUY10 was a remarkable device for its time.
They did work nicely in transmitters, certainly up to 40m with about 3 or 4W output from a 12V supply. They could be amplitude modulated using a small speaker matching transformer with a tap to modulate the driver stage. A suitable circuit can be found in a 1960's Tab book on simple transistorised transmitters. An audio amplifier using a pair of OC25's or similar, in a transformerless output stage, made a suitable modulator.
I have some AUY10's in the stores - might try building a clone of the one I had about 50 years ago!
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