Bob Howell, who works at Prince George's Hospital Center, noticed that the lights on his office phone weren't working last Monday morning.

At the same time, about 11:30 a.m., secretaries at nursing stations throughout the hospital were picking up their receivers and finding no dial tones. Patients couldn't call out. Friends and family members couldn't call in.

Phone workers quickly determined that the telecommunications server had been interrupted and the main switchboard at the hospital was out.

It was time to bring in the hams.

Twenty-nine volunteer amateur radio operators -- also known as hams -- mobilized within minutes, just as they did during Hurricane Isabel last year and the 2002 tornado in La Plata. Before noon, they had arrived with their "go-kits" -- made up of radios, batteries, pencils and paper -- at Prince George's Hospital Center and facilities in Bowie, Cheverly and Laurel that are run by Dimensions Healthcare System. They stayed until after 10 p.m.

"They really played an important role keeping us connected," Howell, director of marketing and public relations for Dimensions, said of the scramble that ensued during the 10-hour, still-unexplained communications emergency. Howell said the hospital's emergency backup system allowed only 25 percent of hospital phone lines to continue working.

With that kind of service, the hospital needed help.

Some of the radio operators stationed themselves at Prince George's Hospital Center. Others were based at other hospitals, clinics and nursing homes run by Dimensions.

If a patient needed to be transported from the Laurel hospital to Prince George's Hospital Center, for example, the operator radioed a ham at Prince George's to see if a bed was available. If a doctor at the hospital needed to get information to an assistant on another floor, the radio operators made the transmission.

The ham radio process, called on when other forms of modern-day communication fail, is slower than instant messaging and cell phones but faster than carrier pigeon and Morse code.

Jim Cross, a ham for 37 years and the Prince George's emergency coordinator with the Amateur Radio Emergency Service, said his hobby, which allows him to talk to fellow hams around the world, becomes the "communication of last resort" when an emergency strikes.

Cross said his group of 85 volunteers across the county includes webmasters, NASA employees, truck drivers and hospital and government workers. Also known by his call sign, WI3N, Cross said that "in real life" he is a remodeling contractor.

"Some people get the license to talk to people around the world," Cross, 56, said. "Some do it to fly model planes. . . . It's a lot of fun, a great hobby."

When Cross is not training other operators for emergencies, he's "rag chewing," which in ham radio speak is spending time talking to someone over the airwaves, he said.

Capt. Chauncey Bowers of the Prince George's fire department said ham radio operators are sought whenever there is a failure or overload of the normal communications system.

"Oftentimes, it's weather-related or a disaster, but it doesn't have to be," Bowers said. "This wasn't a disaster for the community, but it was for the hospital."

Howell said the phone-service disruption allowed Prince George's Hospital Center to see how it would react in an emergency and whether all of its preparations are in place. He said they were.

Where the ham radio operators couldn't help out, the staff did. Carol Bragg, head of the nurses union at Prince George's, said the phone outage sent nurses scurrying most of the day.

"We definitely did a lot of running around," she said. "The nursing staff really stepped it up. . . . If we needed to talk to somebody on another floor, we walked up the stairs. Now we know it's nothing like picking up the phone."