A world of fascinating listening on shortwave radio

If you're getting weary of standard AM and FM radio fare, a veritable smorgasbord of programs awaits you in the in-between realm of international shortwave radio.

Operating between American AM and FM bands (on frequencies that lie between 3 megahertz (Mhz) and 30 Mhz), foreign broadcast services offer programs ranging from news to cultural shows that highlight a country's folk-music traditions. ''Mailbag'' programs answer letters from listeners worldwide over the air.

It's this variety that attracted David Harris, an announcer at WASR in Wolfsboro, N.H., to take up shortwave listening when he was in junior high school. At the time, he says, he saw an ad for a radio receiver that would enable him to tune in on broadcasts from around the world.

''I wanted to be in on that,'' he says, so he bought the unit. And he's been in on it ever since. He says that he's most likely to listen to the British Broadcasting Corporation's (BBC) World Service. He says he particularly enjoys the BBC's dramas and its radio game shows - ''good, high-quality entertainment'' that he says remind him of radio as it used to be. He adds that he regularly listens to Alistair Cooke's ''Letter from America,'' a 15-minute weekly talk loosely constructed around a current news event. (The program can be heard each Sunday at 6:15 p.m. EDT on 15.07, 9.59, 6.175, and 5.975 Mhz.) He usually catches the half-hour ''BBC Play of the Week,'' he says.

For those who seek a bit more armchair adventure, shortwave frequencies also allow a listener to eavesdrop on amateur radio exchanges, ship-to-shore telephone service, commercial air traffic, and some embassy and military communications.

While their precise numbers aren't known, shortwave listeners in the United States are presumed to be a rare breed. WASR's Mr. Harris suggests why:

''In this country, we have a number of broadcast services to choose from,'' he says. A local listener might be able to receive dozens of radio stations and at least four TV stations - many more if there's cable TV in the area. This, Harris says, is not the case elsewhere in the world, where there are many fewer broadcasters and less choice in programming. In many countries, he adds, the government controls the broadcasting. So, to add variety to their listening habits, people there often turn to shortwave radio.

Glenn Hauser, editor of the Review of International Broadcasting (RIB), says another reason for shortwave radio's low profile in America is that it has ''the reputation that it's hard to tune or you hear all these strange noises. I'm afraid Americans have become very spoiled when it comes to what we expect of radio.''

Harris says that reputation is only partially deserved. ''It takes a little more skill to tune in to a program on the shortwave band'' than to AM or FM, he says, but not a great deal more. And he notes that technological advances are making available more sophisticated, but affordable, radio sets that tune at the push of a button.

Harris, who says he has traveled throughout Europe, adds that countries there , with their different languages and cultures, are so close together that there traditionally has been greater interest in international developments among Europeans than among Americans. This translates into a tendency to tune in to find out what's going on in other countries.

''In this country, we just aren't used to anything like that,'' Harris says.

A hint of overseas interest in shortwave broadcasting comes from the Voice of America. One official says that his service ''extrapolates audience figures from a patchwork of surveys.'' Currently the VOA estimates that, worldwide, 100 million people over 15 years of age tune in to VOA at least once a week.

For many shortwave enthusiasts, there is a definite pecking order among radio services. According to an RIB survey to be published in August, the BBC ranks No. 1 among the dedicated shortwave listeners who read RIB. The BBC is followed by two Canadian shortwave stations, Radio Netherlands, Radio Australia, and the VOA.

According to Kim Andrew Elliott, who designed and tabulated the survey, these stations air programs that attract loyal listeners. The majority of international broadcasters, he says, seem to be ''transmitting, but not communicating.''

Mr. Elliott, an associate professor of communications studies at the University of Massachusetts at Amherst, says the BBC is popular with listeners because it has a strong signal and ''pretty much all the programming you want.'' The survey also shows that the BBC's news broadcasts are highly regarded. Elliott says listeners turn to news on shortwave because ''there's not much international news coverage in the American media.''