Path: utzoo!censor!geac!jtsv16!uunet!cs.utexas.edu!tut.cis.ohio-state.edu!ucbvax!pasteur!euler.Berkeley.EDU!dls
From: dls@euler.Berkeley.EDU (David L. Steere)
Newsgroups: sci.electronics
Subject: Undesired radio reception: mechanism?
Message-ID: <19422@pasteur.Berkeley.EDU>
Date: 10 Nov 89 17:19:08 GMT
Reply-To: dls@euler.berkeley.edu (David L. Steere)
Distribution: usa
Organization: University of California, Berkeley
Lines: 24


I read an intriguing newspaper article yesterday, and thought that it
might make an interesting topic for this newsgroup to discuss.  It
concerned the undesired reception by people in the Los Angeles area of
a radio station's transmissions in the nearby area.  Apparently, there
is a strong local station with a narrow transmission pattern, and as a
result, people are apparently finding that they are picking up the
broadcast quite clearly on a variety of items around the house,
including telephones, stereo systems, and even the house water pipe
systems (!).  Now, maybe the newspaper report was exaggerating, but it
seems reasonable that radio broadcasts might indeed be picked up by
poorly shielded electronic devices, whose internal circuitry might
provide the detection/demodulation functions of a simple crystal radio,
resulting in audible evidence of the radio broadcast in a variety of
unwanted areas.  Apparently, the local phone company has been inundated
with complaints, and their response has been that the radio station's
transmission adheres to FCC regulations, but that the various (cheap)
telephones are not properly shielded.  Can knowledgeable readers
comment on the exact mechanism of this pickup, and offer examples from
their own experience?  And, how on earth would a water pipe system pick
up and render audible such radio transmissions?  The article explicitly
mentioned someone who claimed that they were hearing the radio station
while seated on their toilet.  Since the station was broadcasting "rap"
music, one can easily "c" what the end result of this would be...