After nearly three years of nostalgic middle-of-the-road music programming during the day, WWRC-AM (980) announced last week that it will switch to an all-talk format this summer. Half a dozen music show hosts -- including popular Washington radio veterans Ed Walker, Felix Grant and Mac McGarry -- were told they would have jobs until Aug. 3.

The talk format is not new to the 5,000-watt Silver Spring station. It has carried NBC's popular Talknet, featuring financial adviser Bruce Williams and personal-advice host Sally Jessy Raphael, nightly since before New Jersey-based Greater Media Inc. bought the station from NBC for $3.6 million in 1984. NBC, which had owned and operated what was then WRC-AM for more than 61 years, reported losing $2.5 million annually with its six-year-old news/talk formula. NBC officials said that despite the station's respectable ratings -- better than 4 percent of the total listening audience 12 years and older during summer '84 -- the overhead for the network's brand of news/talk was too costly.

"We never inherited those costs," says Ted Dorf, vice president and general manager for WWRC and its consistently highly rated sister station, easy-listening WGAY-FM (99.5). "We will try to keep all our costs in line."

According to the Arbitron Ratings Survey, WWRC's current format has been fairly popular, but declining. The station claimed a 2.4 percent share of listeners 12 years and older in the recent winter period, down sharply from a 3.1 in spring 1986. The ratings also indicate that the station's core audience was typically older than 25 to 49 years old, the age group most sought after by advertisers. Half-minute spots normally sold in tandem with WGAY-FM sell for more than $300, but merchants could expect to pay less than $100 for the same time on only WWRC.

Dorf expects talk to attract "slightly younger demos {demographics}, more in line with WGAY demos."

Rick Sklar, the programmer responsible for building America's premier rock 'n' roll station, WABC-AM in New York City, nearly three decades ago, has been hired to consult during the format change. Sklar also played a large role when ABC changed WABC into the network's talk flagship and built the successful ABC Talk network.

Dorf and Sklar are interviewing possible hosts from around the country, but Dorf refuses to be specific about who'll be hired and what exactly the station will sound like.

"It's too early to tell. Everything is predicated on who's available and what they would bring to the table," Dorf says.

Radio Ripples WWRC-AM's proposed format change is good news and bad for several stations.

Two floors below the WWRC studios in the World Building is WNTR-AM (1050), a struggling 1,000-watt talk station that owners had hoped would be the flagship for the Statesman Communication Network, scheduled to debut in August. But now planners are taking a wait-and-see attitude. Statesman has not signed any affiliates yet.

But over at WWDC-AM (1260), the area's only other nostalgia-format outlet, the WWRC news was good. Plagued by weak ratings -- it's not ranked among the top 20 stations in Washington -- the station has already heard from several of the WWRC announcers seeking employment and is expected to get many WWRC listeners who reject talk. Currently, morning man Eddie Gallaher is WWDC-AM's only live host. Before joining WWRC last year, Ed Walker had been close to signing an afternoon contract with the station.

At news, information and personality WMAL-AM (630), Operations Manager Jim Gallant says, "We aren't expecting any changes here." However, the ABC-owned station recently added evening talk with Dr. Joe Novello and has been adding small amounts of talk programming to its lineup for some time.

WMZQ: A Decade of Country It's been 10 years since oldies station WMOD-FM signed off for the last time, giving birth to country WMZQ-FM (98.7). Mayor Marion Barry has declared Monday "WMZQ Day" in the District as the city's only country station celebrates its 10th birthday. Three years ago Viacom International bought WMZQ-AM (1390), which plays a steady diet of country gold, while more contemporary country artists are heard on FM. To celebrate their decade of country, the stations will host a free concert Sunday at Wild World in Largo featuring Lee Greenwood, the Girls Next Door and the O'Kanes. Gates open at 5 p.m.; the concert begins at 6. Bring a swimsuit. For details, call 249-1500.

Dick Cerri Returns to WLTT After a year at oldies WXTR-FM (104.1), folk expert Dick Cerri will move his "Music Americana" back to CBS-owned WLTT-FM (94.7) in Rockville Sunday evening beginning at 8. Cerri, who was heard on W-Lite from 1981 to '86, will feature Stan Rogers, Peter, Paul & Mary, Ian and Sylvia, Joan Baez, local folk artist Mary Chapin Carpenter, and interviews with Judy Collins and John Stewart.