We've all wanted to strangle them before. There's nothing worse than some jerk blabbing away on their cell phone while you're trying to enjoy a movie, meal at a restaurant, or a nice quiet nap on the bus/train ride to work. Actually, only hearing only one side of a stupid conversation makes us pay more attention than normal. Our brain expects information from both sides of a conversation, and it will try to fill in the blanks. You can try to send the offending mobile blabbermouth a few evil looks or the old "courtesy cough" but those passive aggressive gestures rarely work.

If you really want to shut down a dopey chatter box, then you'll need to acquire a cell phone jammer.

WHAT IS A "JAMMER"?
Cell phone jammers are devices that create a temporary "dead zone" to all cell phone traffic in their immediate proximity. Jammers are typically used by the police and military to control or disrupt communication during hostage situations and bomb threats. Traditionally, jammers were large antennas mounted on trailers that had to be pulled behind a truck. They now come in a variety of shapes and sizes including models that are about the size of a cell phone.

A big jammer Photo from antennasystems.com	A portable jammer Photo from Globalgadgetuk.com

USING A JAMMER
Because jammers now come in much smaller sizes, they are very easy to carry around. Portable personal jammers will fit into the palm of your hand or easily slip into your coat pocket. So the next time someone on your commuter bus refuses to shut up, you can just reach into your backpack and turn on a temporary "dead zone" with your jammer. Then get back to some nice peace and quiet.

RANGE & FREQUENCY
Most jammers only have a range of about 50 to 80 feet and will only effectively jam your immediate surroundings. Mobile blabbermouths will just think they've hit a dead spot in their cell phone company's coverage until they leave your jammers immediate vicinity. Stronger jammers are available to cover larger structures like office buildings, movie theaters and churches. They look like a miscellaneous metal boxes with wires sticking out and are usually mounted on walls or ceilings (see image on right).

Most cell phone jammers come in 2 versions, one for Europe, North Africa and the Gulf states GSM networks (900 & 1800) and one for the Americas & Canada (800 & 1900 mhz) networks. Make sure you get the right version for your location.

WHERE TO BUY JAMMERS
The legality of owning, using and selling cell phone jammers is different depending on where you live. Although its illegal to sell jammers here in the United States, you can easily purchase them from British, Israeli, and Asian electronic web sites. Companies in the UK can sell jammers but it is illegal for civilians in the UK to use them. This weird legal paradox may sound familiar to people who own radar detectors here in the United States.

Sound confusing? Maybe this chart will clear things up:

US civilians looking to acquire a jammer will have to purchase one from Europe or Asia. If you live in the UK, you can only buy a jammer in Asia. And you luckily Asian residents can purchase jammers from the UK or elsewhere within Asia however this may vary from country to country.

Two great sites that sell cell phone jammers are Globalgadgetuk.com (UK) and Antennasystems.com (US). Any site selling jammer will include legal notices to help customers understand any restrictions that may be in place.

Globalgadgetuk.com has this legal note on their web site for UK customers:

Cell phone jamming equipment is illegal to use in the UK as it violates sections 1 & 13 of the 1949 telegraphy act, we are therefore unable to supply cell phone jammers to any UK customer with the exception of certain military and government departments who have the necessary authorization from the UK Office of Communications (Ofcom). Please note that no exceptions can be made on this policy.

Antennasystems.com has a similar note for US customers:

JAMMERS ARE FOR SALE ONLY TO UNITED STATES GOVERNMENT AGENCIES & EXPORT CUSTOMERS. EXPORTS ARE REQUIRED TO HAVE STATE DEPARTMENT APPROVAL (EXPORT LICENSE) - NO EXCEPTIONS.

THE RISKS AND LEGALITY OF JAMMING
The FCC (Federal Communications Commission) in the United States has outlawed the sale and use of jammers because they can in theory interfere with emergency communications between police and rescue personnel, aid in criminal activity as well as disrupt medical equipment like pacemakers.

Even though jammers are illegal, it will be pretty difficult for the FCC to catch you. Triangulating the exact position of someone with a jammer will require some fancy hi-tech tracking gear and several personnel.

However if you do get busted using a cell phone jammer, be prepared for a possible $11,000 fine. Remember, jammers are mainly intended for military or government use.

FOR THE ULTRA PARANOID..
For those die hard jammers out there who don't want to give out a continuous jamming signal that attracts the FCC, you can link a cell phone jammer with a cell phone detector. This way the jammer(s) only activate when they detect a cell phone signal. You can also connect this system to an alarm if you want to be alerted the next time someone is snooping at your weekly Dungeons& Dragons meeting.

Photo courtesy of antennasystems.com

MILITARY APPLICATIONS FOR JAMMERS
The US military routinely uses jammers to protect secure military areas from electronic surveillance. Jammers can also be used to protect traveling convoys from cell phone triggered roadside bombs in places like Iraq.

FINAL THOUGHTS
Banning the sale and civilian use of cell phone jammers in the US and UK certainly has its reasons. You certainly wouldn't want someone's jammer blocking a 911 phone call you're trying to make. For example, a jammer hypothetically could be used by criminals who break into homes and want to prevent any calls for help. However, jammers can also be used for good. Spanish terrorists used cell phone triggered bombs in the 2004 Madrid train bombings. Just think, someone using a cell phone jammer who was only trying to protect themselves from a mobile blabbermouth could have prevented the bombing and saved hundreds of lives.

Maybe someday governments will relax their restrictions on jammers and they will become standard in places like churches, movie theaters and courthouses. Until then, only government personnel. and outlaw jammers will be able to enjoy some peace and quiet at the movie theater or the ride via public transportation to work.