EVERETT — Some homeowners with sweeping views of Port Gardner discovered recently that their panoramas come with a hidden feature.

Starting about Feb. 2, hundreds of people found their garage doors had stopped working.

“I knew right away something was weird,” said Chris Borys, who lives a few blocks from Harborview Park.

“I changed the batteries twice, and I did the whole reprogramming thing using the booklet, and still no luck,” she said.

Her experience is not unique.

Tanis Marsh, who lives on View Ridge Drive, said her garage doors started acting up a week ago.

“Three or four days ago, one of them wouldn’t work, and then none of them would work,” Marsh said.

Dan Clements, who lives on Edgemoor Lane above Harborview Park, said his wife’s garage door quit working last week.

“We actually spent $800 and replaced my wife’s before we learned what was going on,” he said.

What exactly is happening is unclear, but many people suspect activity at Naval Station Everett is the cause.

Since Jan. 30, the base has been participating in Exercise Solid Curtain-Citadel Shield, a regularly scheduled exercise conducted on many U.S. naval installations.

The anti-terrorism and force-protection exercise is expected to end Friday. It includes coordination with first responders and simulated gunfire.

Many garage door openers, especially older models, use frequencies in the 300-400 megahertz range. That’s a part of the electromagnetic spectrum that the Federal Communications Commission has allocated for government use, especially the military.

High-powered military voice and data communications at those frequencies, such as the newer Land Mobile Radio system, tend to drown out low-powered signals when they are in operation.

At that frequency, the radio waves only travel in line-of-sight. So, in Everett, the homes affected by the interference tend to be on bluffs and the waterfront, with enviable views of Port Gardner.

Naval Station Everett spokeswoman Kristin Ching said the exercise isn’t to blame.

“Nothing has been turned on for this particular exercise. So in that regard, it’s highly unusual for us to get interference because of it,” Ching said.

She wouldn’t rule out a source of the interference on the base, however. “The base is still trying to figure out where it could be coming from.”

The interference also doesn’t appear to stem from Naval Air Station Whidbey Island, which is home to many of the Navy’s EA-6B Prowler and EA-18G Growler electronic warfare squadrons.

“It’s very unusual. I’ve been here four years and I’ve never heard of this happening,” said Mike Welding, a spokesman for the base.

NAS Whidbey Island also has been taking part in Solid Curtain-Citadel Shield. If the base planned an electronic warfare exercise, it wouldn’t be a secret, Welding said.

“If we’re flying off the coast and want to do something with jamming or something like that, everything we do has to be coordinated with the FCC and multiple other agencies,” he said.

In the meantime, the phones have been ringing since last week at Overhead Door Co. of Everett, a company that installs and maintains automatic garage doors.

“We’ve probably had in excess of a couple of hundred calls, and we’re just one company,” said Lance Tennison, who works in sales.

“It seems like it happens just about every year, sometimes longer than others,” Tennison said.

Calls are pouring in at the Doorhouse, another sales and service company in Everett.

“It’s been a pretty high volume, that’s all I know,” receptionist Taylor Bailey said.

A significant increase in garage door interference was reported after 1997, when the aircraft carrier USS Abraham Lincoln arrived at Naval Station Everett for a 15-year stay.

In 2004, the U.S. Department of Defense began deploying more Land Mobile Radio systems to military sites across the country, resulting in more reports of interference near bases and other government operations.

There was even one case in Ottawa, Canada, in 2005, which some people suspected originated from the U.S. Embassy.

Periodic occurrences have been reported in Everett over the years, but usually have not lasted as long.

In response to increasing signal interference, some manufacturers, such as Elmhurst, Ill.-based Chamberlain Group Inc., released new products that use different frequencies, thus solving the problem, company manager Martin Heckmann said in a statement.

“I’m told that military bases in some areas have adjusted their RF, which would help mitigate this issue,” Heckmann said.

People can upgrade their garage door systems to the newer models to avoid this type of interference.

The cheaper alternative is to just wait it out. “You have to wait till they get done and then things go back to normal again,” Overhead Door’s Tennison said.

Clements recalled living in Southern California in the 1970s.

“When Nixon flew into Orange County Airport, people in the flight path, their garage doors would go up and down,” he said. People would sit outside to watch the show.

Borys called stores and then the naval base, but nothing has helped. “The guy just said, ‘the captain is aware of the problem,’” she said. “I’m resigned.”

Chris Winters: 425-374-4165; cwinters@heraldnet.com. Twitter: @Chris_At_Herald.