In radio, the adage goes, you don't have a respectable re'sume' unless you have been fired or have switched jobs a few times. The turnover rate among deejays, program directors and news reporters, except for the largest markets, is high.

"Deejays in the top 10 markets last three or more years because they have the union and . . . a certain status. In the markets from 10th to 35th in size, you have people who stay only two years. Some are looking to move up but some have risen to what they aspire," says Dean Landsman, president of Landsman Media, a placement and consultant firm in New York. No firm figures for the turnover rate exist. Landsman says he recently got a re'sume' from a man who had worked at 14 stations in four years. "It turned out he had 12 pieces of bad luck. In radio there is nothing wrong with being fired," says Landsman.

In news departments, a survey by the Radio-Television News Directors Association last year showed 35 percent of news staffers across the nation had been hired within the year, according to its research director, Vernon Stone.

Though Washington is the nation's ninth largest broadcasting market, periodic waves of job switching occur. Melvin Lindsay, an influential deejay, last week left a nine-year perch at WHUR-FM (96.3) for a slot at WKYS-FM (93.9). His temporary replacement is Mansy J. Pullen Jr. Cliff M. Blake, program director at WMZQ-FM (98.7), left the country station this week after his contract was not renewed. Bob McNeill has returned to the station to take over the programming duties. Bob Hughes is back at WLTT-FM (94.7) as operations manager. Bob Cummings, who was named program director last month, is out.

Other changes:

Brute Bailey joins WDJY-FM (100.3) Monday as program director. Dan O'Neil has moved to another United Broadcasting outlet in Baltimore as program director.

Kojo Nnamdi, international correspondent and former news director at WHUR, left to host WHMM-Channel 32's "Evening Exchange."

Arthur Crofton is joining WASH-FM (97.1) from Jacksonville. He will be part of a new morning team scheduled to debut Sept. 2. The station is looking for a female cohost for the show.

Bill Singleton, a k a Willie B. and Bill Reno, left WASH to join a rock band in New York.

Bill Hickok, formerly of Fairfield County, Conn., is now the 5 to 9 a.m. host on WWRC-AM (980). Larry Walton has moved to 1 to 4 p.m. Jack Edwards has joined the station from Baltimore as music director.

Steve Morgan, a veteran of the Charlotte, N.C., and Columbus, Ohio, markets, has joined WTKS-FM (102.3) as news anchor from 6 a.m. to noon.

Toni Zimmer, local host for "Morning Edition" on WAMU-FM (88.5), left for a job in private industry. A 40-Plus Celebration

WWRC received 277 applications for its first annual "Woman of the Year" competition for the 40-and-over age bracket. "I am always looking for something to dramatize the vitality of that group. They have the most income, the most discretionary income, the most leisure," says station manager Ted Dorf, who has been working to change advertising attitudes toward the 35-64 demographic group. Ten semifinalists were selected this week by Dorf and other preliminary judges, who searched for "a well-rounded person, weighing the appearance, background, achievement and talent," according to Dorf. The winner will be selected by seven celebrity judges, at a closed-to-the-public pageant at the Hyatt Regency Hotel on Capitol Hill next Tuesday. Public Affairs

WTOP-AM (1500) is now carrying "Viewpoint" with New York Gov. Mario Cuomo and former Tennessee senator Howard Baker, weekdays at 2:41 p.m. The Mutual Radio program alternates the Cuomo and Baker perspectives. The all-news station is also featuring The Associated Press' "Newsweek On-Air," an hour-long look at the latest issue of the magazine every Sunday at 9 p.m. Still on the air is "Face-Off" with Sens. Robert Dole (R-Kan.) and Edward Kennedy (D-Mass.) at 8:52 a.m. daily. Special Service

WCLY-FM (95.5) will be conducting "Operation: Kid Guard," a free opportunity to have children photographed and fingerprinted to help cope with the problem of lost and missing children. The event will be held tomorrow at the Tysons Corner Center from 11 a.m. to 3 p.m. New Features

WPKX-AM (730) is now featuring the "Kix Country Carryout," an all-request show from noon to 1 p.m. weekdays with Mary Bartone . . . WXTR-AM/FM (1560/104.1) has replaced "Lovers' Lane" on Fridays at 8 p.m. with "Sock Hop," an upbeat party music program hosted by Alex Mitchell.