Fw: Professors worry that engineering students don't tinker - test-drb@ccmp.vtda.org

11 Dec 2000

From: Tony Duell &lt;ard(a)p850ug1.demon.co.uk&gt;

...
 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