Some garage door owners in jam
WASHINGTON — Coming soon to dozens of military bases around the country: radio signals strong enough to jam nearby garage-door openers.
Between now and 2008, the military is supplying a new radio system to roughly 125 bases that uses the same frequency as the one relied upon by more than 90 percent of the remotely operated openers, Pentagon and industry officials say.
It is unknown how many garage doors are close enough to one of the 125 bases to be affected, and Pentagon officials refused to list which bases would receive the new radios. A spokesman said large bases are among those receiving them.
The military radio signal is sometimes so strong that it overpowers the opener’s signal, preventing the door from opening. Or it can also vastly reduce the opener’s range, forcing the user to walk close to the garage before it will open.
Unless another solution is reached, the consumer will either have to live with the inconvenience or pay to fix the problem.
The cheapest fix would be to manually replace parts of the opener so it will use a different frequency — probably a $60 job, said Mark Karasek, technical director of a manufacturers’ group formed in response to the military radio rollout. Calling a technician to do it for you will probably run double that, he said.
This presumes consumers figure out what is wrong. When a garage door doesn’t open, people will generally replace the battery, then the opener itself. A new opener can run $150 or $200 before installation.
Government and industry officials differ on how widespread the effect will be. The government predicts it will be limited; the industry says it will be worse but wants more information from the military.
“These things are generally in a relatively small radius around military facilities,” said Michael D. Gallagher, chief of the National Telecommunications and Information Administration, which oversees government use of the airwaves. “The period of inconvenience is generally around when they start up the system. Generally consumers can try again after letting a short pause go by.”
Linton Wells II, Pentagon acting chief information officer, predicted the effect will only be noticed within 10 miles of a base.
But Karasek said interference may be felt as far away as 50 miles. He estimated that at least 50 million garage-door openers in the United States use the same frequency as the new radios.
Beyond issues of convenience and cost, his group raises safety concerns about people who don’t carry house keys being locked out of their homes.
The garage-door opener frequency at issue — 390 megahertz — has belonged to the military since around 1950. Openers have legally operated at that frequency since at least the early 1980s, Karasek said.
U.S. law allows low-power electronic devices to operate on military frequencies if they don’t cause interference. It was a good frequency for garage-door openers because transmissions can penetrate the doors.