Path: utzoo!utgpu!news-server.csri.toronto.edu!clyde.concordia.ca!uunet!aplcen!uakari.primate.wisc.edu!zaphod.mps.ohio-state.edu!wuarchive!mailrus!accuvax.nwu.edu!nucsrl!telecom-request From: 0003829147@mcimail.com (Sander J. Rabinowitz) Newsgroups: comp.dcom.telecom Subject: Re: Answering Machines as Room Bug? Message-ID: <11340@accuvax.nwu.edu> Date: 25 Aug 90 14:23:00 GMT Sender: news@accuvax.nwu.edu Organization: TELECOM Digest Lines: 42 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 595, Message 6 of 8 In reference to a TELECOM issue of 24 August 1990, Tom Neff 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. . . ". . .So I started unplugging things. Speakers... no. Radios... no. The phone itself... no. The answering machine... YES! . . ." The message went on to ask whether other Panasonic answering machines broadcast on radio frequencies. Tom Neff's machine was a Panasonic KX-T1470. I own a Panasonic KT-T1450 which I had purchased only 48 hours ago on sale at a local KMart, as well as a Sony ICF2010 shortwave receiver, and I wanted to see if I could recreate the above events. As it turned out, when the answering machine was idle but turned on, it did send out signals on 5,655 kHz. I then hooked up my tape recorder to the radio, and deliberately started speaking within various distances from the answering machine. 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. Two other things I noticed with my model: 1) The signal cuts off when the tape players are activated. In other words, it appears that telephone messages do not get sent over the air. 2) The apparent strength of the answering machine signal seemed to depend on whether or not the short wave receiver was plugged into an A.C. wall socket. When it was plugged in, I could pick up the signal as described above, but when the radio ran off of batteries, the receiver had to be practically next to the answering machine for the signal to be received. My tentative findings, then: Yes, the answering machine may be broadcasting, but a) the audio distortion is horrible, and b) the signal may not travel far beyond the confines of your living room. * * * Sander J. Rabinowitz 0003829147@mcimail.com * * *