Xref: utzoo sci.electronics:2325 rec.autos:7391
Path: utzoo!mnetor!uunet!lll-winken!lll-lcc!lll-tis!ames!ucsd!brian
From: brian@ucsd.EDU (Brian Kantor)
Newsgroups: sci.electronics,rec.autos
Subject: Re: Robocop spotted (Photo radar enforcement)
Message-ID: <40@ucsd.EDU>
Date: 24 Feb 88 21:08:48 GMT
References: <602@anasaz.UUCP> <21649@clyde.ATT.COM> <418@flatline.UUCP>
Reply-To: brian@ucsd.edu (Brian Kantor)
Organization: The Avant-Garde of the Now, Ltd.
Lines: 12
Keywords: radar detectors

Just program your scanner to listen for the local oscillator frequency
of the police radio.  For example, if the police frequency is 158.97 MHz
(as it is in my area), and the radio is a Motorola Micor, then the IF
frequency is 11.7 MHz so the local oscillator will be at either 170.67 MHz
or 147.27 MHz (i.e. the channel +/- the IF).  Around here, it's 147.27,
so I just leave my radio tuned to that frequency, and whenever I'm
within a block or so of a police car, my scanner starts to sputter and
belch from the very weak signal radiated by the police car's receiver.

Only problem is that 147.27 is a popular ham radio frequency, so if some
old farts are gassing about their ailments, I don't hear the PD.  But
you might be luckier.
	- Brian