Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!iuvax!cica!tut.cis.ohio-state.edu!ucsd!usc!ucla-cs!oahu.cs.ucla.edu!sprouse From: sprouse@oahu.cs.ucla.edu (Steven Sprouse) Newsgroups: sci.electronics Subject: Re: miniature FM transmitters: bugs Keywords: FM transmitter, bug Message-ID: <35665@shemp.CS.UCLA.EDU> Date: 24 May 90 16:02:40 GMT References: <667@retix.retix.COM> <3197@galena2.UUCP> Sender: news@CS.UCLA.EDU Distribution: usa Organization: UCLA Computer Science Department Lines: 29 In article <3197@galena2.UUCP> smithju@motcid.UUCP (Justin A. Smith) writes: >paulk@retix.retix.COM (Paul C. Kim) writes: > >>considered illegal? How accurately are these little buggers detectable >>via some type of scanner? > >of a quater $29.98). As for the legality of these, its obviously not illegal >to sell them (in kit form), but i suspect that you had better not get caught >using one . > >Justin Smith > Radio Electronics had an article a few years ago about how to detect bugs using a spectrum analyzer. The technique involved making the house quiet, and then scanning the FM spectrum. You then invert and store this background signal. Next you get someone to go screaming through the house making lots of noise while taking a second reading. When you add the two signals you should see a peak where the the second reading differs from the first. This is the bug's frequency. The technique sounded plausible, but I don't have a spectrum analyzer so I can't try it out. I would think it would detect the cheap bugs you find in the hobbyist magazines. -Steven Sprouse ---------------------------------------------------------------------------- "Good marketing replaces good enineering, whether we like it or not."