Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!mailrus!accuvax.nwu.edu!nucsrl!telecom-request From: petrilli@walt.cc.utexas.edu (Chris Petrilli) Newsgroups: comp.dcom.telecom Subject: Re: Answering Machines as Room Bug? Message-ID: <11404@accuvax.nwu.edu> Date: 27 Aug 90 01:41:25 GMT Sender: news@accuvax.nwu.edu Reply-To: Chris Petrilli Organization: The University of Texas at Austin Lines: 39 Approved: Telecom@eecs.nwu.edu X-Submissions-To: telecom@eecs.nwu.edu X-Administrivia-To: telecom-request@eecs.nwu.edu X-Telecom-Digest: Volume 10, Issue 600, Message 3 of 9 In article <11340@accuvax.nwu.edu> 0003829147@mcimail.com (Sander J. Rabinowitz) writes: >In reference to a TELECOM issue of 24 August 1990, Tom Neff bfmny0.bfm.com> wrote the following: >"I turned on the shortwave receiver in my apartment this morning and >was flipping past the 5-6 MHz neighborhood when I distinctly a voice >coming from the speaker. It was my friend in the other room! I >couldn't believe it. . . > [. . .] When I played the tape back, I did >recognize my voice, but it sounded so muffled as to make the signal >useless for intrusion purposes. [... he continues by noting that when plugged into the AC wall socket, he is able to receive a much stronger signal than when running off batteries...] Being someone interested in radio propagation, and working with alot of radio equipment, it would appear to me that electrical circuits in both the answering machine, and your Sony radio are not too well isolated from AC noise. Apparantly, the Panasonic machine is modulating the AC carrier in some way, and your radio is picking that up ... this means that it would most likely be just as strong at your neighbors house (as long as you are on the same power transformer). I could be wrong, but this would be the most likely cause of something like this happening ... you might try isolating the Panasonic from the wall with some sort of line filter (I like the DEC VAX filters myself, but...) that goes through an isolation transformer ... if it still appears, I'm wrong. + Chris Petrilli "Opinons represented here | University of Texas at Austin do not necessarily | INTERNET: petrilli@ccwf.cc.utexas.edu represent those of a sane | SNAILMAIL: 429 Brady Lane, Austin, Texas, 78746 person. Take them as + PHONE: +1 512 327 0986 simply that."