Electronic Weapons: <b>June 22, 2005</b>

June 22, 2005

Garage door openers are under assault by military radios, and its no ones fault. For over half a century, one of the radio frequencies reserved for military use in the United States has been the 380 to 400 megahertz band (FM radio, for example, broadcasts on the 88 to 108 megahertz band of frequencies). For about two decades, manufacturers of garage door openers were allowed to use the 390 megahertz frequency, because the openers were very short range (low power) and unlikely to interfere with military radios (or vice versa). But a new generation of military radios has changed all that, by sending out powerful 390 megahertz signals.

The problem was first noted last Fall, as new radio systems, using the 390 megahertz frequency, were installed on military bases. By 2008, some 125 bases will be using the new radio system. The Department of Defense says that the new radios only make garage door remote control systems inoperable. But thousands of users report that they have seen the garage doors open and close by themselves. Since the garage door system manufacturers are using the 390 megahertz frequency unofficially (but with the knowledge of the government), they will have to change their equipment to use another frequency. That could cost up to a hundred dollars, or more, per system. Garage opener manufacturers, based on reports from their repair technicians, believe that the new radios interfere with garage door controllers up to 80 kilometers from military bases. Thats over 50 million garage door systems.

There will be more problems like this, as more wireless equipment comes into use, and the military makes more use of frequencies they have long owned. It's not a new problem, and was first noted on a large scale during the 1991 Gulf War. Here, there was a large concentration of military equipment form all the American military services, and foreign armed forces as well. There were several unexpected incidents where frequencies collided in unexpected ways. There was some of this again in 2003 in Iraq. There will be more, and some of it will be deadly.