''Keep your dials on rock radio 98. We'll be coming at you with a whole hour of 'The Police,' '' the DJ intones. ''As for weather, there's some clouds on the way later today. . . .''
The voice is the smooth, modulated one of commercial FM radio introducing a program of nationally recognized artists. But is this all that radio is about?
There's a growing group of individuals who would respond with an emphatic ''No!'' They're the same people who are trying to get listeners to tune in to locally produced and oriented noncommercial radio, which switches the voices of trained disc jockeys for those of volunteers.
But cultivating community-oriented radio can often seem as tough as growing vegetables on concrete. Radio listeners have become accustomed to zipping through traffic to the beat of FM-rock and the muted sounds of ''easy listening'' music, or propping up their feet to the highbrow noises of the local classical station.
That's where the National Federation of Community Broadcasters cuts in. NFCB represents an expanding group of noncommercial stations dedicated to filling the airwaves with alternative programming. Although the federation by no means represents all such community-oriented stations, the bulk of them have added their call letters to this organization's roster of 65 stations.
As president of NFCB, Thomas J. Thomas has been helping to nurture stations ranging from the influential and usually highly controversial Pacifica Foundation chain to ones tucked away in rugged outposts in Alaska. His group was formed seven years ago by 15 community-oriented broadcast groups, only six of which at that time were even on the air.
Asked how there could be such growth in seven years, Mr. Thomas commented, ''I think that part of the reason for it is that there is a generation now coming of age that has grown up with electronic media. In the same way, an earlier generation was giving birth to literary journals.''
He also credits his own organization with giving community broadcasting a boost.
There are challenges, though, to further expansion. One is getting frequencies in metropolitan areas, where the FM band is as packed as a salesman's suitcase. Most of the movement's recent growth has been in less populated areas.
Like many others today, Thomas sees a cloudier climate for organizations seeking funding. ''There is clearly less government money available,'' he says. Add to that what he calls a spillover effect, where there is much more competition for private funding. And many stations already have threadbare bank accounts.
This could also affect seed money for launching new stations, which have in the past depended on grants from a variety of federal and local agencies, and from private foundations.
But then, listeners themselves have always been expected to help. Although it is difficult at this point to expect individual contributions to support stations fully, there have been gratifying results. The NFCB estimates that listener support accounts for more than 40 percent of the income of stations.
Although the federation itself can't dish out money, it can help in other ways. Members praise the group's ability to represent them in Washington, whereas a station, say, in Wisconsin can feel it has about as much pull as a toy tractor.
There's four-month-old KCAW in Sitka, Alaska, a small community on Baranof Island where part of the audience is often out crabbing or fishing. (The station's FM signal travels well over water.)
For Rich McClear, general manager, NFCB makes a big difference. ''No one else is really involved in citizen-produced radio except for NFCB. In Alaska you can feel rather isolated from other radio stations, particularly ones with citizen producers, and that link really helps.''
Mr. McClear has done it all in the radio business, including commercial radio in New York. But today most commercial radio is too nationally oriented for his tastes.
''That's one of the main problems with radio. People are used to having other people do things for them. It's very important to promote people making their own music, both in the family and in the commmunity. We let them hear each other and hear themselves.''
No one claims it's easy on KCAW, or as it calls itself, Raven Radio, after a prominent bird in the area. Marika Partridge, the program director, remarks that ''most of our volunteers go fishing, and if you try to pin them down on a time to do a program, they'll say, 'I don't know. I may be going crabbing.' The salmon season has just begun, so we are losing a lot of talented people.''
KOPN in Columbia, Mo., on the other hand, has no trouble rounding up volunteers. Music director Chris Merrick says the station has 100 people all working on programs.
He admits the station can't match the honey-smooth voices of commercial stations. But for him, that's perfectly OK.
''Most people like that 'just folks' sound. It's sincerity that people appreciate. They can even appreciate it when we make mistakes. It makes us more human.''
''When you have a hundred people and each one is planning an intense show,'' he adds, ''you have a lot happening on the radio during one week.'' About 80 shows are aired on KOPN each week (sometimes more than one person puts together a program).
Included in the rich mixture of KOPN programming is a smorgasbord of music and a variety of informational and politically oriented shows. ''Our politics are no politics,'' he remarks. ''The people running the station are caretakers. If you are responsible enough to do a program, you can go on the air.''
On the other hand, there's the Pacifica Foundation's five stations, which have often been called left-leaning. Jim Berland, general manager of Pacifica's Los Angeles station KPFK, admits that ''there is a definite bias'' to the station. But this bias, he says, is toward viewpoints that are not widely heard.
Pacifica has always prided itself in breaking away from convention. In 1949 its original station, KPFA in Berkeley, Calif., first began to break into the relatively quiet FM airwaves. It was the product of a group of pacifists and a pioneer in listener-sponsored radio.
Since then, Pacifica added its station in Los Angeles, and also ones in New York, Houston, and Washington. Serious difficulties resulting from Pacifica's bold and controversial programming style, however, have often pushed its stations toward a precipice, including challenges to their right to broadcast.
''Community radio as a whole is progressive,'' remarks David Salniker, general manager of KPFA. ''Who else is going to allow air time to [ disenfranchised people]?''
According to executive director Sharon Maeda, almost 80 percent of Pacifica's money comes from listeners. Because of this, she says, ''we're free to do virtually everything we want to do.''
Recently, for instance, it gave six straight hours of coverage to the nuclear disarmament demonstrations in New York.
At the same time, the Pacifica stations are an excellent example of locally produced programming. All of the stations have small performance auditoriums from which music can be taped for broadcast or aired live.
Somewhat different in style from Pacifica is WOJB, a station in Hayward, Wis. , that began broadcasting in April. Although it's operated from the tribal office of the Lac Courte Oreilles Indians, the intent is to become a station for the entire region. According to Glenn Hall, station manager, ''The word I take to heart is community. And anyone who is within our signal is in our community.''
For Mr. Hall, all-important is the task of building a bridge between the Indians and other people in the region. This bridging goes on over the air as well as in the studio, where Indian and white volunteers work together.
Before the station went on the air, ''There was a recognized need for better communication on the reservation,'' Mr. Hall said. The tribal newspaper is only published monthly. Robert Albee, director of development, adds ''Local newspapers didn't care about the tribe unless there was trouble.''
Among their programs is ''Drumsong,'' with drum music from a variety of Indian tribes in a number of states. But airing local performers is of paramount importance.