Residents on Mystery Beam Find It a Signal Annoyance

LIVERMORE, Calif. — Hundreds of homeowners in the east San Francisco Bay Area are being confounded by uncooperative automatic garage door openers, thanks to an unspecified government agency transmitting radio signals from a mountaintop, officials said.

“We know it’s a government agency,” Tom Hora, a spokesman with the Federal Communications Commission in Livermore, said Tuesday, “but we can’t say which one.”

He said that residents who cannot tune the openers to another frequency can expect the problem to persist through May 2.

Garage door companies have been swamped with complaints since Friday, when homeowners discovered nothing was happening when they pressed the buttons on the devices that normally save them the trouble of manually opening and closing the doors.

Brian Cross of Cross Overhead Door Co. in Hayward, aware that automatic garage doors operate on radio signals, said he telephoned the FCC to demand an explanation for his sudden increase in service calls.

Cross said the FCC told him that government transmissions were “saturating” some garage-door receivers. He said he was told that the signals were being transmitted from Mt. Diablo, which overlooks much of Contra Costa County.

Brian Carr, salesman at Contra Costa Door Co. in Concord, said he has received up to 400 calls. “All we know is that there’s radio interference in the air from some source--we do not know why,” he said.

The difficulty has been reported in Concord, Orinda, Walnut Creek, Lafayette, Moraga, Danville, San Ramon and Livermore.

Hora said the public was not forewarned because garage door openers are considered “unprotected devices,” although they operate on radio frequencies used by the government and other authorized users.

“We’re not obligated to do anything,” he said. “Normally, though, if anyone were to contact us, we would let them know what the situation is.”