# cell phone blocker?



## splish (Nov 7, 2002)

Does a gizmo exist that would stop cell phones from working? Seems like it could be done by somehow jamming the frequency. I'm just tired of having meetings, classes, and dinners interrupted by inconsiderate jerks. If such a device doesn't exist, someone should invent one. They would make a fortune. And I for one woudn't care if it was legal or not.


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## ntexasdude (Jan 23, 2005)

Yes, movie theaters and restaurants have experimented with the idea. I read about a system that was being tested in Japan. The problem is liability. People that are on call such as doctors and emergency personnel couldn't tolerate it. I'm not aware of anything that like that for personal use. As an old radio guy I know you can get on the wrong side of the law real quick by jamming electromagnetic signals.

What would be cool is a system that automatically sets all phones to vibrate.


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## dave1234 (Oct 9, 2005)

splish said:


> Does a gizmo exist that would stop cell phones from working? Seems like it could be done by somehow jamming the frequency. I'm just tired of having meetings, classes, and dinners interrupted by inconsiderate jerks. If such a device doesn't exist, someone should invent one. They would make a fortune. And I for one woudn't care if it was legal or not.


Yes jamming would be a federal and possibly state crime taken very seriously as this could affect someones life or safety. I understand your frustration but do you really not care?


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## stonecold (Feb 20, 2004)

Jamming is a federal crime... It is also illegal to posses one but you can buy them from mexico no questions asked and they get right through customs. They have some that are smaller than a book that you could leave in yoru book bag or brief case and jam near by cell phones. 

I know of a couple people who have one. One is even in a church another the guy carries it around in his book bag for when he has classes just to keep the it quite in class.


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## Nick (Apr 23, 2002)

splish said:


> Does a gizmo exist that would stop cell phones from working? Seems like it could be done by somehow jamming the frequency. I'm just tired of having meetings, classes, and dinners interrupted by inconsiderate jerks. If such a device doesn't exist, someone should invent one. They would make a fortune. And I for one woudn't care if it was legal or not.


There is no law that would prohibit you from holding your events and dinners in a signal-proof venue sucn as a tunnel, bank vault or underground crypt.


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## DonLandis (Dec 17, 2003)

True, Nick but jamming requires transmitting an RF signal for that purpose which is illegal. Signal proofing a venue is not practical although more times than not signal proofed locations happen by chance. I know as I used to have T-Mobile and that service was blacked out by the least little obstruction. 

If jamming were legal then I would start with putting a radar jamming transmitter in my vehicle.


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## Nick (Apr 23, 2002)

Don, at no time did I suggest active jamming, but simply identifying and utilizing passive _dead-zones_ to one's advantage.

Check the battery in your 'humor' detector!


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## Bogy (Mar 23, 2002)

What you need is a very large "cone of silence."


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## Laverne (Feb 17, 2005)

!rolling

Now THAT'S funny!!!


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## DonLandis (Dec 17, 2003)

Nick said:


> Don, at no time did I suggest active jamming, but simply identifying and utilizing passive _dead-zones_ to one's advantage.
> 
> Check the battery in your 'humor' detector!


Was at 15% after recharge, I see your  at the end. Not used to you delivering absurdity as a form of wit!


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## Bogy (Mar 23, 2002)

DonLandis said:


> Was at 15% after recharge, I see your  at the end. Not used to you delivering absurdity as a form of wit!


Actually, Nick has lost some of his edge lately. Go back in the archives and take a look at his first few thousand posts. Nick was the master of absurdity as a form of wit. Then he got into this whole "curmudgeon" role and got repetitive. This is the real Nick I know and love. :lol:


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## DonLandis (Dec 17, 2003)

Bogy said:


> Actually, Nick has lost some of his edge lately. Go back in the archives and take a look at his first few thousand posts. Nick was the master of absurdity as a form of wit. Then he got into this whole "curmudgeon" role and got repetitive. This is the real Nick I know and love. :lol:


Normally, in this section you make sense but lately, I can't figure out what you are saying. Maybe your battery is in dire need of recharge.


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## Steve Mehs (Mar 21, 2002)

You can find instructions on how to make them online, along with FM jammers, radar jammers, satellite TV jammers. I'd have no problem setting up one in my house, but no one can get cell phone reception in my house so it works out naturally


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## HIPAR (May 15, 2005)

Digital Cell Phones employ a spread spectrum type of signal. This is inherently difficult to jam because the power is spread of a large bandwidth and the jammer will also need to be wideband to out shout all of the signal components. It can probably accomplished a close range with a wide-band noise source optimized in the 1.9 GHz band.

I saw a neat jammer on the web that receives on the phone output band and translates that band to the phone input band (80 MHz higher) to confuse the phone. This methodology should work quite well.

--- CHAS


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