Deejay Vinny Brown had to fake his cheerful fast-talking banter on the air. He had watched Bobby Bennett, a WOL personality for 13 years, end his shift five hours earlier too choked with emotion to say goodbye forever to his audience.

Brown, his severance check in his wallet, took a deep breath and punched the tape cartridge button to play Minnie Riperton's "Back Down Memory Lane." It was, Brown said later, "symbolic of the way things were, how proud people were to have worked for this station and the fact WOL was an institution in this city."

As Gladys Knight and the Pips crooned the last refrain from "neither One of Us Wants to Say Goodbye," Brown sadly turned over the controls to WOL's new owners, Dewey and Cathy Liggins Hughes.

Dewey Hughes slid onto the deejay's chair. It was "a chilling moment," he said later. "Radio station WOL, 1450. The big 'O-L.'" As Marvin Gaye's song "Inner City Blues" filled the airwaves, Dewey stared at the control panel almost in disbelief. Eighteen often frustrating months had passed since Dewey got the call telling him the station that gave him his first broadcasting job was up for distress sale during an FCC investigation of a deejay payola scandal.

When the music died, Cathy heard Dewey say quickly and quietly, "Thank the Lord." Tears filled his eyes. An unopened bottle of Dom Perignon champagne with a red bow sat on the control panel. Feeling the tension, they teased each other, waving fried chicken bones from box lunches. Cathy said, "We is here!"

Thus closed a chapter in Washington's radio history that began in the tumultuous '60s. Dewey and Cathy Hughes in charge, WOL has entered a period of drastic change. The station's programming has gone from youthful glibness to adult sophistication. No more "Good Morning Babycakes" or studio jingles. No more driving disco soul beat "without a message" for the junk-music junkies, Dewey Hughes says, but daytime talk shows with serious themes, spiked with popular music. He envisions radio to teach and inform, not just to entertain. p

"Kids cannot read or write in this town but they can boogie-woogie with the beat and repeat all the nonsense words of these songs. To me the priorities are misplaced," Cathy Hughes says.

"There is nothing on the Am band other than religious programming for black adults in this city," Dewey Hughes says. "There is an unbelievable thirst for information, and black people who may feel uncomfortable calling in to WRC or WMAL can call us and speak their minds."

Blacks have used WOL to speak their minds since 1965, when the big 'O-L' burst rudely unannounced over Washington's airwaves, its deejays irreverently jive-talking, rhyming and ab-libbing news, announcements and commercials. Black Power of the 60s said that it was good to be ethnic, that black was beautiful and that it was okay to say hog maws and chitlins on the air. WOL dejays did just that. The Talk of the Town

But their style wasn't all talk, and included a commitment to public service. They used air time to promote blood drives, black theater and community action forums. Deejays like Bob "Nighthawk" Terry, Rudy "Tall Tanned Texan" and Fred "Agent OO Soul" cajoled, sang and screamed to and for Washington's underrepresented black community. WOL stayed in the top 10 for a decade. And its success made a dreamer out of a station errand runner who wanted to be a deejay.

The errand runner was Dewey Hughes.

Hughes, 41, a tall, quiet man with a graying afro and a full beard that he wears like a steel football helmet, is a child of the city and a respected professional who taught himself to read and never got his high school diploma.

Cathy Liggins Hughes, 32, intuitive, ambitious, feisty but ebullient, is his raging wind. She puffs long Saratoga cigarettes through a cigarette holder and says she's the only woman she knows who has managed three radio stations in the Washington market. She's the initiator of radio station WHUR's "The Quiet Storm" and "The Morning Sound," who managed the talent that brought the station from the ratings cellar to the top 10.

Together, Dewey and Cathy Hughes plan to do the same for WOL. The old unionized staff, too expensive for the new owners, is gone. Gone, too, are the lovable, boisterous Petey Greene and his partner, Herb Barksdale, once hosts of a popular Sunday evening call-in talk show that offered amazingly accurate and insightful streetcorner interpretations of current events. Greene's show opened the airwaves to callers expressing their own views.

The Hughes format will increase audience participation in topic discussion. "You won't hear about Johnny Jones and his friends over on 14th Street who got shot over a crap game," says Hughes. "This time, we call all the shots."

The Hugheses seem earnest and sincere, but the truth is that WOL had begun to change its format to fight its competition in less drastic ways before they got the keys to the station. In the early '70s, for instance, WOL deejays were fired if they didn't tone down their banter and shorten it to compete with the growing FM radio market, which played more music with less talk. FM stations used stronger signal equipment that reached more listeners and offered better musical sound than AM stations.

Says Bobby Bennett, one of WOL's best known personalities, no longer with the staff: " 1,000-watt station like WOL cannot compete with a 50,000-watt station that reaches all the way to Breezewood, Pa. The ratings are taken on about a 100-mile area, and if they do ratings all the way to Gaithersburg and you can't reach that far, man, you're suffering. Blacks started moving to the suburbs in the '70s, and they began listening to stations that were more powerful because that was all they could get." Top-10 Tenacity

One of those FM stations, Howard University's WHUR-FM, then managed by Cathy Liggins, won substantial numbers of listeners with its urbane, sophisticated, mellow programming. After 1975, WOL's ratings dropped from the top 10 on a downward slide to 17th out of 30 today.

Dewey and Cathy Hughes believe they know what Washington's black community wants to hear, and say that the city needs alternatives in black media programming. "Remember, I grew up here," Dewey Hughes says.

The oldest of six children from a Southwest Washington family, Dewey was too embarrassed to let others know he couldn't read. He attended three local high schools without ever getting a diploma. He finally taught himself to read, and how to operate a radio station, while working as an errand runner and then public affairs director for WOL. He got a producer's job for Petey Greene's local television show, later winning several Emmys for the shows he produced at Channel 4 in the mid-'70s.

"Dewey is a perfectionist and a taskmaster who expects the best," said Sandra Butler, executive producer for programming at Channel 9.

Dewey met the engaging Cathy Liggins when she was the general manager of WHUR. She was angry about losing her "Quiet Storm" host, Melvin Lindsay, to a competitor, WKYS, and Dewey helped get Lindsay back to WHUR. Cathy remembers, "Once Melvin was gone, I was angry and I was hurt. Dewey, who was a producer at the time, called me and said Melvin really should be on WHUR and why don't we get together for lunch and talk about it. We've been having lunches and dinners ever since."

Cathy, the maverick daughter of a famous jazz-musician mother and a conservative, middle-class certified public accountant father, took the reins of WHUR with little experience but plenty of guts. Responsibility and challenges were not new to her. At 14, she lied about her age and got a job as a telephone operator working 40 hours a week after school with the Omaha, Neb., telephone company.

At age 17, she had married, had a child and divorced, taking on the responsibilities of parenthood alone. In the late 1950s, she placed herself at the forefront of the Omaha civil rights activities and was thrown in jail.

Rodney Wead, who was a community activist there, remembers the feisty, 105-pound, afroed Cathy in the fray between activists and police inside of the Omaha Civic Auditorium when George Wallace came to speak.

"She was a fireball," says Wead, now an executive with a national community action agency in Chicago. "It was Cathy who helped push for the first black-owned radio station in Omaha. We could see then she was a diamond in the rough."

Journalist Tony Brown brought her to the Howard University faculty in the early '70s to help him start the School of Communications. Within three years she became the station's general manager and a battle-scarred veteran of a union strike, internal university squabbles and staff dissension.

Some who have worked with Cathy say that she is aggressive and abrasive, that she has often pitted people against each other.

"In radio, the measure of success is the ratings," says Clint Walker, the only original staff member left at WHUR now. "Cathy rubbed a lot of people the wrong way, including me, but she made a believer out of me because some of the moves she made that I was completely against turned out to be the right moves."

Former WHUR deejay Dyana Williams remembers another side of Cathy Liggins Hughes. "She's a black woman living in a predominantly white society. A black person in any profession feels the pressure for achievement, for success," says Williams. "Being a woman manager in this country is especially difficult. She has the drive of a locomotive, she's like a rocket on a launching pad. She will say what she feels without thinking whether or not this is going to hurt someone. But I've also seen Cathy be caring and loving." The Format of the Future

Cathy Hughes dismisses her detractors' sentiments with a shrug and a laugh.

When she's accused of being arrogant, she says she's just confident. "I don't want to hear about the problems in a situation, I want to hear solutions," she says, inside her office near WOL's entrance. "People are looking for movers and shakers in the world and I want to be a mover. We deliver."

"What they are trying to do is to hold an audience with a music base and then bridge and intersperse the time with talk," says Phil Watson, the first station manager of WHUR radio and an executive with the Corporation for Public Broadcasting. "That format can work very well, and it is the genesis of the sophisticated nighttime hotlines that are popular on WMAL and WTOP radio. People will tune in if they expect to hear something interesting, but the drawback is that it could become heady and dull."

Autorama Cab driver Morris Settle, who listens mostly to AM radio, and has been a WOL fan for years, says he and his wife have been listening to the new format, but are so far undecided. "I like not having a whole lot of rap, but the rap thing sort of growed on me. Things change and you got to accept that. My wife says the shows keep her busy while she does the housework. I think a lot of us old timers will listen after we get used to the changes."

Sixteen-year-old Michael Mork, a Southeast Washington apprentice carpenter, says he likes the new station format, but when it come to music, he would rather listen to an FM music station.

"We're giving them a chance to express themselves," says Rudolph Brewington, the morning talk show host known as "talk master," and he continues, "to be in touch with elected officials. We also give them uplifting, inspirational music that often complements the topic of the morning."

On a recent show, for example, the topic was adoption, and the music played between the blocks of conversation included the songs "Young Child" by Ronnie Laws, "Just a Little Loving," by Sarah Vaughan and "Believe in Yourself," By Lena Horne.

Inside the control booth, Brewington abandons his suit jacket, loosened his tie and rolls up his shirt sleeves. "My next guest certainly need no introduction," he says, his butter-smooth baritone oozing from the speakers. "He is someone who has been on the cutting edge of the civil rights struggle for more than a decade: Julian Bond.

"Julian, can you assess the Reagan presidency, what it's going to mean for minorities?" Brewington asks. "Our listeners are invited to express their views."

His phone lines light up.