WPFW-FM, Washington's "melting pot" radio station, passed its sixth anniversary Monday with its perennial shortage of funds and its license under attack, but the managers and volunteers who keep the station on the air are determined to maintain the sound that one official called a "legacy of the '60s."

Executive producer Robert Frazier, sitting amid empty reels and recording equipment in his paper-strewn office at 700 H St. NW, reflected recently on the station's difficult past.

A programmer across the hall spun a be-bop jazz album, while producers in an adjoining room planned an upcoming show.

"There's a great deal of love and commitment here," Frazier said over the rumble of a Metrobus making its way down H Street. "It's either to the music, the humanistic politics, or the cultural growth that is experienced here at WPFW. The opportunity for creativity and flexibility is all here."

What makes this listener-supported public station unusual in Washington goes on behind the scenes. More than 200 volunteers give up time and money to play their favorite music on the jazz format, learn broadcasting or air their political views to anyone listening to 89.3 FM.

"No other radio station has 200 volunteers," said Marita Rivero, WPFW's station manager. "WPFW is a melting pot of all ages, nationalities, religions, and political perceptions. All points of view are expressed here and I like that--it allows you to stimulate ideas."

What she asks of the on-air people is that they "take their mission as a broadcaster seriously and that we be a forum for ideas. We can't be predictable," she said. "I want the station to sound like my living room, with hot discussions on a variety of subjects."

Critics have charged the station with having too many "hot discussions" since it first signed on February 28, 1977 with Duke Ellington playing "Take the A Train." One of the more controversial talk shows featured two Iranians presenting an alternative viewpoint when 52 Americans were being held captive in Iran.

WPFW was accused in an article in Spotlight, the publication of Liberty Lobby, a self-described ultra-conservative organization with a national following of more than 300,000, of being pro-communist and supportive of foreign regimes hostile toward the United States. Tax dollars are being spent, the article said, to support "ultra-left, anti-American propaganda."

The conservative American Legal Foundation has petitioned the Federal Communications Commission to deny the renewal of the station's license on various grounds, including violation of the fairness doctrine and discrimination against the handicapped in the station's building design.

"ALF wants broadcasters and their audiences to know that the time has come to put an end to vociferous special-interest groups harassing broadcasters and dictating programming and hiring decisions," said ALF's general counsel Daniel Popeo in a press release last July.

A decision is expected in about three months in the case, which has been pending before the FCC for more than a year, according to Mark Solberg, supervising attorney for the commission. Solberg said the ALF charges that WPFW has not offered "reasonable opportunity" to present contrasting viewpoints, a violation of the fairness doctrine, which could be grounds for denial of a station's license.

The allegations are untrue, according to Art Cromwell, music director at WPFW, who called ALF a "hit group."

"We're not communist or left wing," he said. "We just have a variety of ideologies here. They (ALF) didn't even deal with our variety of programming here."

"We do more than just play records," Cromwell said. "WPFW is a legacy of the 1960's. . . . WPFW is the logical step from activism in the streets to examing issues . . . and to exposing people to a wide spectrum of hues of ideologies and thoughts over the airwaves.''

Without the support of commercial or corporate money, WPFW has had to rely entirely on the donations of its approximately 5,000 members and on grants, primarily from the Corporation for Public Broadcasting and the National Endowment for the Arts.

"The money is the bottom line," said Rivera. "How to move us into financial stability is the challenge." The station operates on a $265,000 annual budget.

As a member of the Pacifica Foundation, an organization of five public stations nationwide, WPFW is barred from accepting corporate funding to underwrite its shows--a prohibition that limits its resources, but pleases some of its personnel.

"We'd rather be responsible to our listeners than a large multinational corporation," said executive producer Frazier.

More money could allow the station to purchase a building, renovate and better equip the studios, hire additional staff, and broadcast more live news and music events, just a few of the items on the station management's wish list.

"We are hampered in the ability to expand and do creative productions," said Frazier. "You can't create a masterpeice if you don't have the paint and brushes."

Ratings released recently by Arbitron, a national radio and television survey company, show that listenership increased from 70,000 in 1981 to 155,400 last fall.

The more than doubled listenership may be attributable, in part, to Arbitron's improved system of surveying black audiences. WPFW estimates that 68 percent of its audience is black. So, while there is no question that the station's listenership is getting larger, the amount of growth is unknown.

"We didn't open bottles of champagne when the ratings came," said WPFW development director Lenore Gardner. "But we do know that the station has grown."

More than anything else, the station is known for its jazz programming, which Cromwell said is the best of its kind in the country.

"Our collection . . . is second to none," said Cromwell. "I get calls from musicians who tell us they've never heard such a good variety of music."

The music heard on the 50,000-watt station, whose listenership stretches nearly 100 miles, is mostly paid for by the individual programmers, who buy the records they play. "I spend money on the music because I feel very strongly about doing a good show, plus jazz is one of my life's inspirations," said Cynthia Dawn Weaver, one of the stations's broadcasters.

"I'm committed to making this station survive, and I have to do something tangible to see that happen," said Weaver, who also volunteers six hours a week stuffing envelopes, answering phones, and keeping track of the small donations that come into the station every day. "People realize the rareness of the opportunity here."

The overall programming draws praise even from some competitors. "WPFW provides a great service to the large international community in our area," said Michael Nitka, acting station manager and program director at WAMU-FM, the most listened-to public station in the area and the fourth most popular in the nation.

On Monday, the station observed its anniversary by airing taped segments of its first broadcasts. A larger celebration is scheduled for later this month. "We all feel good today," station manager Rivero said. "You could say there is contained rejoicing."

Reflecting on WPFW's beginning, Rivero said: "There were some flubs, but there was also a freshness in the air. It hadn't been sanitized out of existence.

"I just love this station and it is going to survive."