Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!apple!agate!telecom-request From: kitty!larry@uunet.uu.net (Larry Lippman) Newsgroups: comp.dcom.telecom Subject: Re: Home Telephone Tap Detector Message-ID: Date: 21 Mar 91 04:08:23 GMT Sender: Telecom@eecs.nwu.edu Organization: TELECOM Digest Lines: 74 Approved: Telecom@eecs.nwu.edu X-Submissions-To: telecom@eecs.nwu.edu X-Administrivia-To: telecom-request@eecs.nwu.edu X-Telecom-Digest: Volume 11, Issue 222, Message 1 of 8 In article 8156boydk@vmsd.csd.mu.edu (Kevin Boyd) writes: > In my latest issue of the Hammacher Schlemmer catalog, there is a > device called the "Home Telephone Tap Detector". It's description > really sounds too good to be true, but Hammacher Schlemmer is a very > old (founded in 1848) and reputable company. Don't forget the old saying that if it sounds too good to be true, it *is* too good to be true. > HOME TELEPHONE TAP DETECTOR: Used by law enforcement agencies around > the world, this home telephone tap detector detects and defeats > virtually all tap systems. "Law enforcement agencies around the world", eh? I wonder if these are agencies which enforce Barnum's Law ("There's a sucker born every minute."). > It employs four individual detection systems to detect low and > high impedance taps, wireless bugs, off-hook extensions and > automatic tape recorders. What, no capability to detect "medium impedance" taps? > Mode one scans the line for > any low impedance taps or off-hook extensions and, if any are found, > an indicator light goes out and your phone conversation is > automatically muted. Mode two scans the radio spectrum for any > operating wireless taps within or in the vicinity of your telephone, > then automatically switches to mode three which actually deactivates > any taps or tape recorders. Mode four nullifies any transmission > bugs. Metal unit is RJ-11 compatible and can be connected in seconds. > Comes with an impact resistant carrying case, line jack cord and one > 9-volt battery. 7/8"H x 3"W x 5 1/2"L.(.6lb.) 35664X..... $199.95 "Mode one" is reminiscent of the screw-in handset transmitter replacements sold under such tradenames as "Eavesdropper Stopper". A voltage comparator senses any off-hook voltage below an adjustable threshhold and assumes that such a reduction is the result of parallel DC resistance from an off-hook extension telephone. Unlike the handset device, it would appear that this gadget operates a relay to mute the associated telephone set. "Mode two" sounds like a broadband RF detector using a simple diode feeding a high-gain amplifier and comparator circuit. Detection of RF above such a threshhold probably operates the same muting relay used for "mode one". I'd bet money that this gadget doesn't have the sensitivity to detect a one watt VHF transmitter just 100 feet away. Does anyone think that a perpetrator actually planting an RF transmitter is going to be dumb enough to place it right next to the telephone set? "Mode three" sounds like the condition when "mode two" operates the muting relay. "Mode four" sounds like "mode three". Well, I guess four "modes" sounds better than two "modes". "Nullifies any transmission bugs", indeed! I wonder if the humongous amount of energy available from the nine-volt battery is used to generate high power RF pulses that will destroy the offending transmitter? I'm also truly impressed with the advanced technology that has permitted this sophisticated unit to be built in a case the size of a 3x5 card and less than one inch thick. The nine volt battery and two RJ-11 jacks will occupy 1/4 of that volume alone! Moi, sarcastic? Why, perish the thought! :-) Larry Lippman @ Recognition Research Corp. "Have you hugged your cat today?" VOICE: 716/688-1231 {boulder, rutgers, watmath}!ub!kitty!larry FAX: 716/741-9635 [note: ub=acsu.buffalo.edu] uunet!/ \aerion!larry