Alan Burns, program director of WRQX-FM (107.3), who turned the contemporary hits station into a model for other Top 40 stations over the last five years, is leaving in two weeks to start a consultancy and to invest in radio properties.

"It was just good timing," he said. "I was given an opportunity to get some equity and to continue to be involved with radio programming." When he joined Q-107 in 1979 it ranked 17th in the market. Today it holds third place, is constantly in the top five and is one of the most visible stations in the market. "We have calculated that in the last year alone 1.25 million people attended events we cosponsored -- the Fourth of July, the annual beach party, Adams-Morgan Day and the New Year's Eve party," said Burns.

The beach affair, by the way, is tomorrow from 10 a.m. at Lake Fairfax Park in Reston. Geronimo's Stand

Don Geronimo, the zany afternoon guy at WAVA-FM (105.1), was suspended Wednesday after he walked off his show the night before with 30 minutes to go. This was preceded by Geronimo's reading of a memo from program director Smokey Rivers on the air and calling Rivers "a jerk." "You don't get up and leave work in the middle of a radio show . . . I don't know whether he is coming back or not," said Rivers, announcing what was called an "indefinite" suspension. WASH Response

More than 300 recipients of the mass mailing from WASH-FM (97.1) boasting about its 4-month-old "exciting new sound" have scribbled positive responses and sent the letters back. "In terms of awareness, it is a perfect campaign," said general manager Tom Durney. First the station introduced a television ad with the bearded Durney talking to Scott and Katie, two "listeners" from central casting. After a few days of prominent plugging, WASH mailed a one-page letter, again with Durney's picture, to 750,000 households. "I thought the TV ad would double the number of people opening up the letter," Durney explained. The full impact of the ads won't show up until the summer ratings survey.

Other WASH news: Barry Chase, a veteran of 20 years as an announcer, was switched from the mid-afternoon shift to mornings this week after the abrupt departure of Tom (Dude) Walker, and Wally Hindes succeeds Shannon LeHere as news director. They join several people Durney has brought on since January, including Toni Trueblood, morning news anchor; Piper Ann Dankworth, traffic reporter; Gary Alan, 10 a.m.-to-3 p.m. host; and Blair Garner, 7 p.m.-to-midnight man. NPR Business

In order to keep its weekend edition of "All Things Considered" and its arts and performance programs on the air in fiscal 1986, National Public Radio is developing a temporary purchase plan for its 251 stations to buy them directly for the first time.

Although 85 percent of the stations carry the weekend news show and 98 percent carry some arts programs, they refused to allocate NPR an additional $1.2 million it requested for fiscal 1986, and asked instead for the individual program costs -- which should be completed next week.

All contracts between NPR and the Corporation for Public Broadcasting, including those for news and arts programs, expire Sept. 30. This plan was prompted by CPB's approval of only $11.3 million for these services instead of an NPR bare-bones request for $12.5 million. NPR's board last week approved a $22 million budget for fiscal 1986, an increase of slightly under $1 million for fiscal 1985. While extremely conscious of belt-tightening, the stations did vote to kick in $270,000 for partial cost-of-living increases for the NPR staff. Payroll Comings and Goings

Jim Bohannon, anchor of Mutual Radio's "America in the Morning," which was recently picked up by WNTR-AM (1050) for the 6 a.m. slot, has signed a new two-year contract. Besides his news magazine show, he does "The Jim Bohannon Show" on WTOP-AM (1500) Sunday at 12:06 a.m. and "Lifestyle Reports" on WINX-AM (1600) every hour from 6 a.m. to 7 p.m. . . . Joe Palka has joined WMAL-AM (630) as production manager and host of the 10 a.m.-to-2 p.m. Saturday and 1 to 7 p.m. Sunday shifts. Bulletin Board

WKYS-FM (93.9) will broadcast live from the Potomac Riverfest on the Southwest Waterfront tomorrow from noon to 7 p.m. and Sunday from 2 to 7 p.m. . . . Tom Gauger of WMAL will be emceeing the "Best of Broadway" with the Fairfax Symphony at 8 p.m. tomorrow at Fairfax High School . . . WMAL is cosponsoring a benefit for Native American children at Pierce Street Annex, Sunday from 4 to 9 p.m., with host Ted Danson . . . WXTR-FM (104.1) will be spotlighting car songs this weekend. You can refresh your memory with "Little GTO" by Ronnie and the Daytonas, "Little Deuce Coupe" by the Beach Boys and "Beep Beep" by the Playmates.