Fw: Professors worry that engineering students don't tinker

From: ajp166 <ajp166_at_bellatlantic.net>
Date: Mon Dec 11 21:07:01 2000

From: Tony Duell <ard_at_p850ug1.demon.co.uk>


>Anyway, one such book (aimed at older children I guess) was called
>'Making a Transistor Radio'. The set was built on a wooden board, using
>woodscrews and screwcuop washers as terminials (and thus no soldering
was
>involved). You started out making a crystal set, then added a single
>audio stage (OC71), then a second stage (another OC71), then added a
>loudspeaker (using an LT700 output transformer). And finally you
replaced
>the crystal detector with the OC45 regenerative stage.


It's been years since I built that way but the first transistor design I
did was
back in '65 with my first "RF' transistor 2n384. It was regenerative.
The
battle (for me) back then I lived less than a mile from 3000W daytime AM
radio station. Not listening to that was indeed a learning expereince.

>Hmm, I'd never want to build a live-chassis set. Isolated PSUs seem like
>a very good idea on experimental designs...


I'd agree but it was a cheap circuit.

>Never built a valve radio. Built other valve stuff over the years,
though...


It good fun. I did one recently on maple (real wood breadboard) using
some of the talves (tubes) provided by one of the members. I went
for the classic Q5er, 4 tubes in all, osc/mixer feeding a regenerative
IF at 455kc followed by one stage of audio. Makes a fair shortwave RX.

Radio is one thing I still enjoy.

Allison
Received on Mon Dec 11 2000 - 21:07:01 GMT

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