From: firstname.lastname@example.org (John Crighton)
Subject: Re: Crystal radio
X-Newsreader: Forte Free Agent 1.21/32.243
NNTP-Posting-Date: Thu, 17 Oct 2002 09:40:33 EST
Organization: OzEmail Ltd, Australia
Date: Wed, 16 Oct 2002 23:51:25 GMT
On Wed, 16 Oct 2002 21:58:41 +0100, "Mr_Ree"
>> Crystal earphones are not very sensitive. You'll be lucky to hear
>> anything unless you have an AM station very close.
>I must disagree!!! I built many crystal sets as a kid (I'm 40 now) and had
>great results with a crystal EP! I still have ther same one and am thinking
>of making another set for old times sake. I still have some OA90 & OA91's in
>my drawers somewhere and some enamalled copper wire (again from the same
>time - I'm glad it doesn't go off!). Ohhhhhh - I'm in the mood RIGHT now -
>where's me soldering iron.......
Hello John and Mr Ree,
this thread has brought back many happy memories for me. I used
the crystal ear piece also but found that they were not as good as
my high impedance head phones. As a boy, I had an assortment of
germanium diodes and would select the best ones by the following
Wear the headphones.
Clip antennna to one side of headphone connection.
Clip earth to other side of headphone connection.
Pick up diode for testing and place it across the headphone
connections. The radio stations were all heard in a jumble
of sound. Some diodes were much better than others.
Funny thing, a few decades later I was working as a field service
technician. The P&O ship Fairstar, a regular visitor to Sydney
harbour, needed some work done on one of its transmitters on
a Sunday. The RF metering circuit needed a germanium diode,
(suppliers were closed). so I drove back home to my place and
robbed one of my child hood crystal sets for an OA81 diode.
Everytime I see that cruise ship being advertised on TV for rich
people to take holidays on it, I keep getting mixed feelings,
remembering that it is using one of my best OA81's selected by
me as a pennyless kid decades earlier ....heh heh heh.