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From: jans@tekgvs.LABS.TEK.COM (Jan Steinman)
Newsgroups: sci.electronics,rec.ham-radio
Subject: Re: naive question about RF propagation (anecdote)
Message-ID: <6671@tekgvs.LABS.TEK.COM>
Date: 15 Jan 90 19:48:56 GMT
Followup-To: sci.electronics
Organization: Tektronix Inc., Beaverton, Or.
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<We all know that AM broadcast radio fades when you drive under a bridge but FM 
doesn't tend to nearly as much. Why is this?>

I'll leave the real answer to someone else, but thought readers might enjoy an 
anecdote on the subject.  The following paraphrased letter to the editor 
appeared in Radio Electronics magazine in the mid-sixties:

"When I drive through a tunnel, FM is okay, but all AM stations suddenly 
vanish.  What should I do?"

The editor at the time (whom I believe was the same guy that edits Popular 
Communications today) replied:

"Stay away from tunnels!  You're a menace to the entire AM broadcast industry!"

(Hope this was helpful, Phil!  :-)

							   Jan Steinman - N7JDB
					Tektronix Electronic Systems Laboratory
					Box 500, MS 50-370, Beaverton, OR 97077
						(w)503/627-5881 (h)503/657-7703