‘Gremlins’ wreak havoc on wireless devices Published Jan. 12, 2009 By Mr. Kenneth Lemke 55th Wing installation spectrum manager OFFUTT AIR FORCE BASE, Neb. -- If you live on or near a military installation, it is quite possible you've experienced a garage door mysteriously opening ... or refusing to open at all. Maybe some days your remote starter works and some days it doesn't. Are these devices broken or can the problem be traced to those infamous 'gremlins' that plagued our pilots and cartoon characters during World War II? The answer lies in the fact that most of these remote control devices have been granted permission by the Federal Communications Commission to operate smack dab in the middle of a band of frequencies authorized for military communication. And, there's a good possibility a military radio system could be causing the interference. These remote control devices, and many more, are technically referred to by the FCC as "Part 15 Devices." 46CFR Chapter 1, Part 15 establishes the rules for low-powered radio frequency transmitting devices that may be operated without a license, and that's what these little critters on your key fob or visor really are - unlicensed radio transmitters. When you purchased your devices, there was a page in the instruction book that had a caveat about the nature of Part 15 devices, specifically stating that there was a possibility they could be interfered with or jammed by licensed radio transmitters. By not requiring a license to operate, the FCC has allowed a whole world of remote control and remote operation possibilities. But with that comes a pesky downside. They're really second-class citizens in the world of radio transmitters, and since they're very low power, they will lose virtually every battle they engage in with those radio transmitters of the licensed, higher-power nature. Is there any recourse for the consumer? Unfortunately, not really. But there are workarounds. Many manufacturers are now making available systems that "frequency hop," so if one signal doesn't work, it changes frequency and tries again. In other cases, a relatively inexpensive retrofit kit to work on a different frequency will do the trick. Most area installers are aware of what the situation is like in any given neighborhood, so it would be best to consult the pros. You may also want to check with your neighbors and see if they've encountered any problems with their wireless devices. If they haven't, consider purchasing a device on the same frequency.