Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!ucsd!sdcsvax!ucsdhub!hp-sdd!hplabs!hpfcdc!hpfcdj!myers
From: myers@hpfcdj.HP.COM (Bob Myers)
Newsgroups: sci.electronics
Subject: Re: wireless electricity
Message-ID: <11170005@hpfcdj.HP.COM>
Date: 2 May 89 18:00:11 GMT
References: <736@ultb.UUCP>
Organization: Hewlett Packard -- Fort Collins, CO
Lines: 25

>>Greg Wageman writes:

>Hmm, I guess you must be too young to remember crystal radios?  These
>were radios that used a diode (originally, a germanium crystal and a
                                             ^^^^^^^^^
>Nope. Iron pyrites (fool's gold).

>Isaac    isw@cup.portal.com

Actually, BOTH materials, along with several others, can be used as the
detector in a "crystal set"; Greg's right, though, in that the "classic"
"cat's whisker" set used a germanium crystal.  You had to hunt around on
the crystal for a "hot spot" at which the "cat's whisker" could be placed to
obtain the necessary diode action.  Not much real power here, though (notice
how cleverly he ties this all back to the original posting! 8-))

As mentioned above, many minerals can be used - I seem to recall reading of
a WW I (or II?) "survival tactic" which involved building yourself a crystal
radio out of a lump of coal balanced on the edges of two razor blade nailed
into a block of wood!   


Bob Myers  KC0EW   HP Graphics Tech. Div.|  Opinions expressed here are not
                   Ft. Collins, Colorado |  those of my employer or any other
{the known universe}!hplabs!hpfcla!myers |  sentient life-form on this planet.