Marvin Mandel is ready for the broadcasting big time, but is the big time ready for him?

It has been more than a year since the former Maryland governor began a daily magazine-format call-in show on WNAV-AM (1430), a 5,000-watt local station, and thus far, he is no threat to Larry King. Days go by and nobody calls. "We don't encourage them," Mandel said. "We figure if people want to call, they'll call, but I don't go in for announcing the phone number every few minutes."

Despite the puzzling public silence, WNAV's sister station, powerful 50,000-watt WHFS-FM (99.1), is planning to expand Mandel's range within the next few weeks by putting him on on Sunday mornings, probably at 10 a.m., for an hour-long monologue wrapping up the news of the week.

"We're doing it because we got so many complaints from places like Rockville and Gaithersburg, from people who want to hear the show but can't get it" with WNAV's limited range, said Jake Einstein, who owns both stations.

So if everyone wants so badly to hear it, how come nobody calls in?

Probably the simplest and fairest answer is that as a talk-show host, Mandel makes a very nice ex-governor.

"He has a way of making things kind of boring," said Annapolis contractor Jim Pickett, who listens because the radio in his pickup truck is AM-only and is semi-permanently locked on WNAV. "He drones along, and after about five minutes you say, 'What am I listening to this for?' and you do this," he said, jabbing a finger angrily at an imaginary car-radio button.

Mandel has a way of ferreting out dull and noncontroversial subjects and raising them to new levels of noncontroversial dullness.

Take last week, when he had as guest one day the police chief of Annapolis, John Schmitt. Here was an ex-governor, convicted of racketeering and mail fraud, who had served 19 months in jail, interviewing the chief law enforcement officer of a city that recently settled out of court a grievance by black officers claiming they were discriminated against in hiring, promotions and assignments.

With all that fodder for spirited discussion, Mandel's first question to Schmitt was: "How did it feel, moving from a big department like Baltimore to a smaller one like Annapolis?"

Somebody find the No-Doz.

The following day Mandel was host to the commander of the local Coast Guard Auxiliary on the topic of boating safety.

"Tell us," said the ex-governor to get the discussion off and running, "a little bit about the history of the Coast Guard Auxiliary."

Just drop that radio here in the bathtub, please.

Nonetheless, Mandel evidently has a small, loyal, local following.

"I like the show," said Ted Levin, son of the owner of Chick and Ruth's Deli, where the ex-governor has breakfast most weekday mornings.

"More intellectual people listen to it, and they're not the kind to call in," Levin said.

"The things he talks about make sense, and the guests are very interesting," said Levin. "Other shows just go after stupid things to get people to call. If you want people to call it's pretty easy -- just talk about things they hate. This show is more positive."

Some politicians like it. "I was on with [Maryland Waterman's Association President] Larry Simns just after we announced the rockfish ban," said state Natural Resources Secretary Torrey Brown, "and it wasn't dull that day."

Mandel remembered that session, too, recalling with pride that he'd mediated between the two, avoided a shouting match, "and by the time they left they were talking about how to solve their problems instead of arguing," he said.

Clearly, Mandel enjoys his public platform.

"He's like a kid with a new toy," said Del. Thomas Mooney (D-Prince George's), a recent guest. "It's a way for him to gain news, keep in touch with politics, and it gives him a forum. A lot of us feel that's really the reason for the show. It's good for him, psychologically."

Einstein, the station owner, said Mandel didn't miss a day of work for a year and only recently took his first vacation -- a week in the Caribbean.

"I do enjoy it," said Mandel. "It gives me a chance to express my opinions, and I learn something new every day. And I think it's sort of caught on. So many people who used to call me governor are calling me Marvin now."

He even gets the occasional letter.

"Here's one," said Mandel, pulling from his pants pocket a crumpled graph paper with a message in ink. It was from a University of Maryland law student, asking if he would address the student's class.

"And here's another one," said the ex-governor, unfolding another crumpled sheet from a different pocket. "That's two in one week."