WDCU-FM (90.1), the University of the District of Columbia's jazz and gospel station, this week named its director of marketing, Edith Smith, acting general manager.

Smith succeeds Godwin Oyewole, who planned the station for the university and served as general manager since it went on the air May 8, 1982. Oyewole, a lawyer, left this week to return to his practice.

"Our station is one that doesn't give people too much talk, just jazz and gospel music, and some worthwhile educational and cultural programming. I am trying to increase the visibility by having bigger promotions. I would like to go to advertising on bus panels, get our people out more frequently," said Smith.

Smith, a native of Norfolk, Va., joined the station last May. She previously worked at WHUR-FM (96.3) as promotions director, and also worked press advance in the Mondale-Ferraro campaign and was a reporter for The Virginian-Pilot for seven years. She is expected to serve as acting general manager until the university names a permanent successor to Oyewole in late summer.

WDCU has an annual budget of $266,000 from the university and currently has two full-time paid staff members. Most of the shows on the station are done by 30 paid part-time staffers and volunteers. The station recently added a business program, "Start-Up," with host Peter Woolfolk, at 3:30 and 6:30 p.m. on Thursdays. This Sunday at 1:30 p.m. it begins a live show, "The Role of Philosophy in Teaching Reasoning and Writing," with Albert Mosley, chairman of UDC's philosophy department. On April 20 at 1 p.m. it will add "Programme D'Ici," a show of French music and interviews with Beatrice Braude.

The station is a partial beneficiary of tomorrow's tribute by the Charlin Jazz Society to composer and singer Stevie Wonder. Charlin will be raising money for its summer intern program and WDCU at an 8 p.m. concert at the Duke Ellington School of the Arts. Blossoms

Joining Cherry Blossom Festival activities next week will be: Dave Arlington and Bill Hamlin of WLTT-FM (94.7), who will escort the princesses at the official welcoming ceremony at noon Monday at Connecticut Connection; Larry Walton of WWRC-AM (980), who will emcee at the Cherry Blossom dance 8 p.m. Wednesday at the Sylvan Theater; Bill Hickok of WWRC, who will host the festival's Grand Ball at 8 p.m. next Friday at the Omni Shoreham hotel. The station's official band, Tom Cunningham and the WRC 980 Orchestra, will perform. A Baseball Pilot

A program about another spring pastime, baseball, gets a tryout on WAMU-FM (88.5) tomorrow at 11 a.m. The station will broadcast an hour-long pilot, "The Saturday Baseball Spectacular," from Dallas with host Norm Hitzges and guest Roger Angell. The show includes a phone-in segment. Ray Davis' bluegrass show will start at noon . . . On Monday, the first day of the new baseball season, WWDC-AM (1260) will rebroadcast the final Washington Senators game at 8 p.m. It was played on Sept. 30, 1971, against the New York Yankees, which the Senators had to forfeit because the fans stormed onto the field. WWDC's Ernie Kaye will host a 30-minute pregame discussion of Washington and baseball . . . In other sports news: WCXR-AM (730) begins the new season of the NASCAR racing circuit at 12:45 p.m. Sunday with the Valleydale 500 from Bristol International Raceway. New Shows

WWDC-FM (101.1) has added "The 11 O'Clock Blues," a survey of rock and blues with Ernie Kaye, Saturday at 11 p.m. . . . "Reelin' in the Years," a weekly look at the music of the last 25 years, debuts on WCLY-FM (95.5) Sunday from 5 to 8 p.m. This replaces the Beatles show, "Ticket to Ride." Money

During a recent 12-hour radiothon, Bill Mayhugh of WMAL-AM (630) collected $500,644 for the Leukemia Society of America.

Songs WCXR-FM (105.9) is sponsoring an "All Request Weekend" starting at 3 p.m. today and ending at 9 p.m. Sunday . . . WHUR-FM (96.3) will play "Marvin Gaye: The Legend Is Forever" Sunday from 1 to 3 p.m. Gaye was killed two years ago this week . . . WETA-FM (90.9) airs the Metropolitan Opera Mid Atlantic Regional Final Auditions Sunday from 7 to 10 p.m. Eight area singers will compete. Remotes and Appearances

Don Geronimo and Mike O'Meara of WAVA-FM (105.1) will be visiting Players in Georgetown tomorrow from 1 to 3 p.m. . . . Dave Kellogg of WMZQ-FM (98.7) will be doing a remote from the Dominion Aquatic, a Woodbridge store, tomorrow from 1 to 3 p.m. . . . The store is in Woodbridge off Route 1 . . . Adam Smasher of WWDC-FM will be hosting a junior "lookalike" contest 6 p.m. Monday before the wrestling program at the Capital Centre. at 6 p.m. Youngsters between 6 and 14 years old are invited to dress like their favorite wrestling superstars.