On Friday, 26 February 2016 09:55:38 UTC, The Natural Philosopher wrote:
On 26/02/16 03:01, tabbypurr wrote:
On Thursday, 25 February 2016 22:21:13 UTC, Andrew Gabriel wrote:
In article ,
"Dan S. MacAbre" writes:

Apologies to those who know about this stuff, if this is a stupid
question. Seeing the electronics thread reminded me of some of my
mis-spent youth. I never knew enough about electronics to design
anything, but I could usually get something like an amp or a tape
recorder from the tip, and fix it. That was about my limit. I used to
enjoy making crystal radios from some of the bits I'd have lying around,
but no matter what I used, I only ever seemed to be able to pick up what
seemed to be radio 4. If you were to build one nowadays, would there be
any suitable non-digital station left to pick up?

Funny you should mention this...
A couple of weeks ago, I stayed over at my parents, and in the bookshelf
was my old Ladybird book on making a radio, which takes you through the
stages of making the receiver and then adding an amplifier to it.
If you can still buy OC71's, it would still work today. ;-)

http://www.mds975.co.uk/Content/geor...trf_radio.html

Unusual method of biasing/driving the OC71.
Indeed. The first transistor radio I built was a 27Mhz RC radio and it
was biased like that. It worked. Until I left in on a window sill in the
sun. I then discovered things like 'temperature stability'...


Last time I looked you could still buy germaniums, albeit a very minimal range.


lots of dealers in old new stock as it were. Same as valves.

Last time I looked I found new ones at Rapid. That was over a decade ago though. Not sure what anyone does with them any more.


NT