Without a lot of test equipment that would be worth more than your car and that you wouldn't want to fuss with, the only practical way I can think of to quickly separate phone and ear in the car ahead of me is to send a burst of broadband noise aimed in the direction of the offending vehicle. I am thinking that 12 dBi gain would still be a relatively small Yagi or log-periodic from 850 - 900 MHz....
on 1/10/02 7:01 PM, George Stults at [email protected] wrote: > Depending on the type of Cell phone I don't think you'd need to jam it. > For analog, just acquire the frequency in use and transmit the tone/signal > for 'END' to hang it up. > The cell site will disconnect the call. (Please Note: This is my theory - > not a reported experiment.) > For digital you'd have to figure out what (CDMA/TDMA/GSM) channel is in use, > a little harder, > and with digital, the encryption scheme might also get in the way. I don't > really know. > But, at least its fun to think about while your following the car slowly > down the road.... > > -George S. > -----Original Message----- > From: Ken Javor [mailto:[email protected]] > Sent: Thursday, January 10, 2002 1:32 PM > To: Chris Maxwell; Cortland Richmond > Cc: [email protected]; [email protected]; > [email protected] > Subject: Re: Car EMC, was bulk current injection testing > > > A lot of humor is based on a deliberate misinterpretation of a common phrase > or common wisdom. "Take my wife, PLEASE," Or the cute stress relief advice > I got the other day. "To relieve a headache, fetch a bottle of aspirin and > follow the directions: Take two aspirin and keep away from children." > > In this case the apparent contradiction is not one at all. The automobile > requirements enforced on emissions protect radio receivers in other > automobiles and fixed radio receivers operating near roads, the immunity > requirements protect your car from malfunctioning when Mr. Richmond's > rolling radio station is in the vicinity. Emission limits protect broadcast > radio reception, while immunity limits protect non-antenna equipment from > high powered transmissions. > > Not wishing to start another long thread, but I know I am not alone in > fantasizing about building a cell-phone jammer and operating it with glee > when I follow some slow driver weaving down the road ahead of me with a > phone cemented to his/her ear. > > on 1/10/02 4:03 PM, Chris Maxwell at [email protected] wrote: > >> That's interesting!! (See Cortland's message below) >> >> We as manufacturers have CENELEC and the FCC breathing down our neck >> over a few dBuV/m. >> >> We have the IEEE EMC and Functional Safety paper, all 50 some pages of >> it, worried about the possibly catastrophic effects of a Palm Pilot next >> to a crock pot. >> >> Meanwhile...Cortland ("KA5S" which stands for "Kills your Auto for 5 >> Seconds") here is running around town with 100Watts of electronic >> ignition stopping transmitter wired to his car. >> >> I mean, I like the job security of being a compliance guy and all... but >> why do we bother? >> >> (Just meant as humor; I hope no offense is taken. However, if you >> think about it, all humor (including this email) needs to have a grain >> of truth to be funny. >> >> Chris Maxwell | Design Engineer - Optical Division >> email [email protected] | dir +1 315 266 5128 | fax +1 315 797 >> 8024 >> >> NetTest | 6 Rhoads Drive, Utica, NY 13502 | USA >> web www.nettest.com | tel +1 315 797 4449 | >> >> >> >> >> >> >>> -----Original Message----- >>> From: Cortland Richmond [SMTP:[email protected]] >>> Sent: Thursday, January 10, 2002 1:30 PM >>> To: Ken Javor >>> Cc: [email protected]; [email protected]; >>> [email protected] >>> Subject: Re: ISO 11452-4 Bulk Current Injection Test >>> Requirements >>> >>> >>> A worst case -- "real world" -- is probably just behind a radio >>> equipped car, mounting a capacitively top-loaded >>> antenna at its rear edge, and about 600 watts of RF. >>> >>> With rather less power, 100 watts, I've occasionally seen adjacent >>> cars' engines stop when I transmit. It would be >>> interesting to see if RF at these levels got into electric cars' motor >>> controllers. >>> >>> Cortland - KA5S >>> >>> (What I write here is mine alone. >>> My employer does not >>> Concur, agree or else endorse >>> These words, their mood, or thought.) >>> >>> >> > > > ------------------------------------------- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > > To cancel your subscription, send mail to: > [email protected] > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Michael Garretson: [email protected] > Dave Heald [email protected] > > For policy questions, send mail to: > Richard Nute: [email protected] > Jim Bacher: [email protected] > > All emc-pstc postings are archived and searchable on the web at: > No longer online until our new server is brought online and the old > messages are imported into the new server. > ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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