From: Chuck Simmons
Organization: You jest.
X-Mailer: Mozilla 4.61 [en] (X11; U; Linux 2.0.33 i586)
Subject: Re: Crystal radio
Date: Sat, 28 Sep 2002 21:38:35 GMT
NNTP-Posting-Date: Sat, 28 Sep 2002 14:38:35 PDT
> I've got a nephew I'd like to show how to build a crystal set, like I did 30
> years ago.
> Anyhow, does anyone know where to get the high impedance crystal earphone?
> How about a source for the venerable 1N34A or any other better device
> recommendations these days?
> Looking to do the typical crystal set, that doesn't utilize a battery, just
> a wire antenna, coil, capacitor, diode and earphone.
The canonical crystal set was made from a variable capacitor, a coil, an
ear piece from a telephone, a safety pin and a galena. Proper
construction was critical. The nails used as terminals had to be nearly
rust free. The coil had to be wound on a dur-dur. In case you don't
know, a dur-dur is the cardboard tube inside a roll of toilet paper or
paper towels. The technical name, dur-dur, derives from the fact that
when you were five, you probably marched around the house with one of
these pressed to your mouth saying "dur-dur-dur-dur-...-dur." In a
pinch, an iron pyrite will work in place of a galena. The base is,
naturally enough, a board. The Dave Berry article, "How to Make a
Board," explains this well but don't use your board to kill spiders as
the electrical leakage through spider guts may reduce the performance of
These radios work best with very long antennas. Do not try to drag the
wire across your neighbor's roof while he is at home. It's really very
hard to explain what you are doing and why.
Once the device is assembled you are ready to test it. You will find
that moving the safety pin point around on the galena or the pyrite is
more effective at tuning than the capacitor. The capacitor is really for
looks. After all, whoever heard of a radio without one. Not having the
capacitor would be like making a 1950s SF movie without a Jacob's
Now that your radio is working and you have become adept at tuning, the
real challenge comes. Finding anything at all worth listening to on
... The times have been,
That, when the brains were out,
the man would die. ... Macbeth
Chuck Simmons firstname.lastname@example.org