Crystal Radios (was Re: List spammer ID'd) - test-drb@ccmp.vtda.org

30 Mar 2001

  Sure, albeit a less "authentic" one.  I've always heard that
germanium diodes are better for this (does this have something to do
with their forward voltage drop of 0.3V vs. silicon's 0.7V?)...like
the venerable 1N34A.

        -Dave McGuire

On March 30, Richard Erlacher wrote:
...
  Well, if the purpose of the crystal + (what we used
was a safety-pin) is to
 function as a diode, then is it still a crystal radio if a diode is used
 instead?

 Dick

 ----- Original Message -----
 From: "Tony Duell" &lt;ard(a)p850ug1.demon.co.uk&gt;
 To: &lt;classiccmp(a)classiccmp.org&gt;
 Sent: Thursday, March 29, 2001 10:58 AM
 Subject: Re: Crystal Radios (was Re: List spammer ID'd)

  >
 > When I built mine, we (the CubScout pack) used toilet paper roll cores which 
we
  > varnished and then applied our magnet wire. 
We even went rock hunting to  find
  > galena crystals to use.  I don't
remember any sort of diode ... there  could've
 > > been one, though ... that was nearly 50 years ago, after all.
 >
 > The galena + catswhisker is a (poor-quality) diode.
 >
 > My suggestion to use a ready-made diode (in the UK I'd use something like
 > an OA81) is that you know that diode is good. You can then wind the coil
 > and wire up the rest of the set, knowing that if it doesn't work the
 > problem is not due to the fact you've not found a spot of the right
 > impurities in the crystal. When you've got it working, you can then swap
 > the diode for the crystal and catswhisker, knowing that if it doesn't
 > work the problem is with that.
 >
 > Otherwise there are too many variables IMHO.
 >
 > -tony
 >
 > 