Bruce Kelly started his night shift at top-40 WPGC (95.5 FM, 1580 AM) last night, slipping semiquietly into the 6-to-10 p.m. chair of gone-West Don Geronimo.

Kelly is 25, originally from Northern Virginia. WPGC program director Steve Kingston found him at Y-100, which is either the name of a motorcycle or a Miami rock station.

"Yeah, there's a lotta heat out there," Kingston allowed yesterday, speaking of nighttime music-radio competition in Washington. "That's why we took our time finding Bruce."

The following is a brief synopsis of the aforementioned heat:

As far as the teen-age audience goes, Kelly has to contend with Q-107's world-class wacko Uncle Johnny (who slipped to a mere 22.5 share of the 12- to 17-year-old audience in his time slot this summer). Also powerful among the young at dark: the lovely and talented Candy Shannon of the urban and contemporary WKYS-FM (93.9), and the somewhat less lovely Mike McKay of album rock DC-101.

The competition gets easier as the prospective audience gets older -- but that's easy as in easy listening: Melvin Lindsey's mellow "Quiet Storm" on WHUR-FM (96.3) and the beautiful music of WGAY (99.5 FM, 1050 AM) will also make Kelly's life difficult. And KYS' Shannon also does well among older listeners, according to recent Arbitron figures.

Next Week's Topic: Has a deejay ever died of having too many syllables in his name?

"The Odyssey of Homer," a series of eight hour-long episodes hosted by Ed Asner and starring Barry Morse, Irene Worth and Shepperd Strudwick, debuts at noon Saturday on WETA-FM (90.9). "Odyssey," produced, written and directed by Peabody Award winner Yuri Rasovsky of Chicago's National Radio Theatre, is the first of 18 NRT dramatizations to be heard in the same time slot in subsequent weeks. (The NRT season spans 52 weeks and the works of such storytellers as Bret Harte, Charles Dickens, Harold Pinter, Jack London and Eugene O'Neill.)

It is commercial-free, scrupulously produced and sporadically brilliant. On top of that you can wax the floor while it's on.

The program debuted this week on about 250 stations, both commercial and public, with an unusual fanfare funded in large part by TRW Inc. (You may have heard commercials promoting the show on such stations as WMAL-AM, ads made possible by TRW's $750,000 commitment to the show.) "Odyssey's" two-year production was underwritten by the National Endowment for the Humanities, the Markle Foundation, the Mellon Foundation and the Satellite Development Fund.

Exiting the Red Line at Farragut North this Friday at 12:30 p.m. will put you in the middle of a live, six-hour remote broadcast by public radio WAMU-FM (88.5). WAMU is celebrating its Actual 20th Anniversary on the sidewalk at the Connecticut Connection (Connecticut Avenue at L Street NW), featuring Ed "Play It Again" Walker, Jerry "Bluegrass Country" Gray, local personalities and either a cast of thousands or the cast of "Evita," depending on who pays for the farecards . . . Mitch Clarke, music director at gospel WUST-AM (1120), is the new program director at competitor WYCB-AM (1340) . . . National Public Radio won two 1980 Armstrong Awards in New York last week: Second place in the education category went to NPR's "Options in Education: Race Against Time," and second place in the news documentary category for its "Not So Placid: the 1980 Winter Olympics."