There's a new jazz radio announcer in town - at WPFW-FM, the Pacifica outlet here.

But spinning records is only his hobby. He spends most of his time in the halls of Congress advocating such legislation as passage of a full employment bill or sponsoring a gun control measure.

However, Rep. John Conyers Jr. (D-Mich.) says jazz is part of his basic lifestyle. "I grew up in an area in Detroit with lots of musicians," explains the seven-term congressman. "Sonny Stitt and Milt Jackson were there. I went to Northwestern High School with Betty Carter. And Tommy Flanagan and Kenny Burrell and I were at Wayne State University together."

"Detroit was just a hotbed of activity. I grew up liking jazz. And I enjoy talking with these guys on the air. It's entertainment for me. I like to get into the inner dimensions of musicians - what kind of society they'd like to see, their political views, their eccentricities. Clearly, just playing records isn't my bit."

His show is called "Jazz From the Hill." Like other WPFW programs during the station's fledgling period (it came on the air on Feb. 28), the Conyers show is not aired on a regular basis.

So far his programs, running about two hours each, have been structured around Conyers interviewing individual musicians and playing their records. The congressman has interviewed Dizzy Gillespie, Clark Terry and Eddie Jefferson. An upcoming program will feature baritone singers and an interview of Johnny Hartman.

The format is casual - in the manner of two old friends sitting in easy chairs generally discussing their personal responses to music and life. And the congressman asks straight forward questions that elicit informative - and often humorous - answers of interest to aficinados and the uninitiated alike.

Many of these musicians are old friends of Conyers, who turns 48 on May 16. He says he's close to Gillespie, Stitt, Jackson and Ron Carter. The congressman was also friendly with John Coltrane, whom he calls the "quintessential musician" and his favorite performer.

It's easy to feel his enthusiasm when he's pacing the floor of his office, speaking effusively of the lyricism of Charlie Parker or the harmonic explorations of Coltrane. He listens to music in his office on a small stereo system.

The congressman's interest isn't just limited to listening for pleasure. He's concerned about the welfare of musicians and the future of their art, and how the federal government can help support jazz.

"We should bring in the artists and have them tell us what their vision of government support for the arts is," Conyers amplifies in soft, measured tones. "Maybe we could bring in 100 artists - and get the National Endowment for the Arts involved. I've talked with the Smithsonian and Endowment people about this."

Conyers says there is no specific program mapped out for such a gathering, but he'd like to pull it off by the end of the year.

The congressman says that any records he plays on his show are by artists he likes. The period of jazz he is most interested in is the '50s and early '60s.

"Jazz has been part of my lifestyle," Conyers explains. "It's an authentic interest because it came from my friends and neighbors whose experiences were not unlike mine."