Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!uwm.edu!cs.utexas.edu!uunet!sjsca4!greg
From: greg@sj.ate.slb.com (Greg Wageman)
Newsgroups: sci.electronics
Subject: Re: Undesired radio reception: mechanism?
Message-ID: <1989Nov13.191239.25082@sj.ate.slb.com>
Date: 13 Nov 89 19:12:39 GMT
References: <19422@pasteur.Berkeley.EDU> <1044@umigw.MIAMI.EDU>
Reply-To: greg@sj.ate.slb.com (Greg Wageman)
Distribution: usa
Organization: Schlumberger ATE, San Jose, CA
Lines: 32

Opinions expressed are the responsibility of the author.

In article <1044@umigw.MIAMI.EDU> wb8foz@Mthvax.Miami.Edu (David Lesher) writes:
># I read an intriguing newspaper article yesterday, 
>[]
># concerned the undesired reception by people in the Los Angeles area of
># a radio station's transmissions in the nearby area. 
>
>Locals will tell you that people with tin roofs heard them.  Farmers
>out working on barbed wire fences heard them. (Those who grabbed long
>wire fences often felt the burns too!) Cars talked. Some dentists found
>out those patients hearing voices in their heads were NOT crazy.
>
>But the fact of the matter is, all it takes to detect AM is a diode.

Yeah, but that doesn't answer the original question, which was: how do
the electrical signals get transduced into audible vibrations?

Why does that pulsing DC in the tin roof make it vibrate?  I am
familiar with the piezoelectric effect, but how many common materials
actually exhibit it?

Or is it the earth's magnetic field interacting with the induced field
from the pulsing DC?

Or is this another urban (rural?) myth?


Copyright 1989 Greg Wageman	DOMAIN: greg@sj.ate.slb.com
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