HOW DO YOU pull a limping radio station from the basement of the Arbitron ratings and haul it right to the top? You go with the grooves, says Donnie Simpson; it's all there in the grooves.

Simpson's the man who took WKYS (93.9 FM) to No. 1 in the spring Arbitron ratings, bumping longtime champ WMAL -- and just to prove it wasn't a fluke, he's kept it there so far, two quarters in a row. As program director, Simpson found the strategy came naturally.

Take 1974, when something about the song "Bennie and the Jets" caught his ear. At the time, he was the number one deejay in Detroit, ruling the night shift airwaves from his soul-station mike.

Simpson was taken by the muted falsetto, the recorded applause and the piano pounding. But "Bennie and the Jets" was an Elton John song, and "black folks hadn't ever heard of Elton John."

"I debated for two weeks," says Simpson, but he finally played the cut and "it was immediately the most requested record." The song soon shot to No. 1 in Detroit, then New York, Chicago and Philadelphia. Simpson got a call from Elton John.

"Hey, it's going black! That's what I've always wanted," John told him, and promptly called a press conference in Detroit to confer upon Simpson the gold 45. It now hangs right by the door in Simpson's family room, the track lights beamed directly on it.

"I just went by what was in the grooves," says Simpson, now 28. "I don't believe in research, surveys and passive call-outs. I always figured that if the music was good, even blue people with purple polka dots will like it."

IN JUST five years, Simpson, one of NBC-Radio's only black programmers, has molded WKYS' floundering disco format into what he now wisecrackingly terms "dis-dat" ("you know, a little of 'dis,' a little of 'dat' ").

It's a chancy fusion of rock, soul, jazz, disco and anything else he thinks his listeners will take to, a format in which you might hear James Brown and the Doobie Brothers back-to-back, a format termed, in current radioese, "Urban Contemporary." And it draws both black and white listeners.

Simpson also doubles as morning deejay. He makes the half-hour trip from his Silver Spring split level in his dented '78 Monte Carlo, dons his earphones, positions himself in front of the oversized mike -- chatting and chortling his way through the 6 to 10 a.m. drive-time slot, always closing with an inspirational round of the Commodores' "Jesus Is Love."

He is a cinnamon-colored "boy-next-door" with perfect teeth and a perpetual smile. "Even my downs are highs," he says. Music is -- and always has been -- a big part of Simpson's life. By the age of 11, he was manning his mother's record store; by 15, he had his own radio show, and now he savors the stuff at home from Technics speakers bigger than his 7-year-old son, who is coincidentally nicknamed "D.J."

Friday morning. 9:52. Time for Simpson's weather forecast:

"Sunday -- partly sunny with high in the mid-50s . . . Uh, no, 70s . . . Well, we can make that mid-50s or mid-70s -- whatever. Doesn't matter. It's a WEEKEND! DO YOU REALLY CARE!!!"

"I blow it all the time," says Simpson, now seated at his mahogany desk, fitted in a gray pin-stripe suit, looking more the businessman than deejay. "Generally, my mistakes are the highlight of my show. If I have to cough, I cough. Usually I manage to hold my sneezes. But if that happens, I just say excuse me and move on. Hey, we're human just like anybody else."

His velvety voice, back-slapping humor and hearty laugh have lured a 9.5 percent share of the area's morning listeners, making his show No. 2 to WMAL's Harden and Weaver (14.4). In a market where that team has held the top morning spot for 16 years, he figures it's as good as he can hope for.

FIRST, HE was "Devastating Don," a hip-talking, fast-rapping, street-chanting deejay, who slurred his slang in the archetypal jivespeak of the early 1970s. He was a teen-ager parroting a fad on the top soul station in Detroit. At the time, it was "in" to be cool.

Then came "Donnie the Luvv Bugg," the number one jock in Detroit for four straight years who took his image "to the max" when he bought a brand new, bright orange Volkswagen and a license plate reading, "THE BUG."

In between, there was college (he graduated from the University of Detroit in 1976), marriage (he exchanged vows with his wife Pam at the age of 19) and a gold record presented to him by Elton John.

Then came KYS.

Seven years ago, KYS was WRC-FM, piping beautiful music just right for shopping centers and doctors' lounges, but limping in the ratings races.

In 1975, when disco started to snowball, NBC converted its floundering D.C. station to the 125-beats-per-minute, thump-thud format. The station settled in the top five for about a year and then took a nosedive when the "hustle" was no longer in style.

Enter Donnie Simpson, at the peak of his super smooth "Luvv Bugg" phase at WJLB. He had been working on his diaphragm since college and now had an ultrasophisticated, talk-show voice, perfect for WKYS' new contemporary format.

But transplanted to the afternoon drive-time slot, Simpson was forced into the station's plastic disco package, with across-the-board restrictions on what the deejays could say or do.

The year was 1977 and the ratings dropped -- again. This time, KYS was beaten by WHUR, a "progressive jazz" station. Management decided to try its hand at jazz.

To Simpson, the station's six-month flirtation with "The Sound as Sophisticated as Washington" was, in a word, "torturous."

The deejays had to read all their lines from cue cards and could only talk 15 seconds on the air. "Would you believe that the general manager actually walked around with a stop watch?" Simpson says, still aghast at the thought. "I lived for 7 o'clock when my shift ended. We weren't even allowed to speak in sentences."

Deejays could only introduce a song, he explains, clearing his throat for an example, with something like this:

"Jazz . . . Mangione . . . 9-3-9 . . . Donnie Simpson . . . K-Y-S . . . 3:18."

"You would actually get a call from the program director," he remembers, "if you slipped and said, 'I'm Donnie Simpson.'

"I envisioned some listener taking his radio to the stereo shop and saying, 'Hey, this thing ain't got no verbs!' "

TWO YEARS of the automaton deejaying . . . and Simpson called it quits. Reluctant to lose his senior staffer, the station's general manager offered Simpson the job of program director.

"I went straight home and spent the whole weekend carting all my albums," he says. "It had gotten to the point where I couldn't even look at my records anymore. It hurt me so bad to see all the stuff we weren't playing."

Simpson took over in 1979, the year the station's ratings hit rock bottom -- No. 16 with a 2.4 share. Simpson shelved the assembly-line disco, lifted the deejay restrictions and quickly hauled in Teddy Pendergrass, Steely Dan, the Eagles, Angela Bofill, Queen, Patti Labelle, oldies, ballads, rock, Top 40, soul, easy listening and jazz. Now it has a 10.2 share.

With that record behind him, Simpson is now in the process of renegotiating his three-year, six-figure contract with the help of Jeff Southmayd, the attorney who represented former WWDC (DC-101) deejay Howard Stern.

"It's hard to sit and watch other morning guys make twice as much as I do for half the task," explains Simpson, alluding to his dual role as program manager and morning drive-time deejay.

"It would be different if I weren't No. 2 in the morning or if the station weren't No. 1. I'm just looking for parity with the other morning jocks." (Elliot and Woodside of Q-107, for example, have a million-dollar contract spread over five years.)

One problem Simpson has managed to avoid is network meddling in his "gut-reaction-based" programming techniques.

"They stay away from me," he says, "because they don't understand what we do. They don't even try anymore.

Simpson pays little heed to trade publications and refuses the overtures of record promoters. "I never cared if a song was No. 8 with a bullet in Billboard. My listeners don't get Billboard. I look at all that stuff in two minutes and say, okay, now give me the Rick James album."

SIMPSON'S HAZEL eyes laugh with him as he describes the hardest part of his job: waking up. On his first day on the 6-to-10 a.m. shift, "I got up at 5 in the morning, staggered into the studio and said, 'Oh Lord, I have to do this tomorrow, too?' "

That was two years ago and Simpson -- being "a night person" -- still hasn't gotten used to it. "I can't remember a single morning that I was excited my alarm clock went off. I didn't even know there was 5 o'clock in the morning until I got this job."

His show is speckled with personal tidbits, Simpsonian commentary and anecdotal family tales -- like the one about his 3-year-old daughter, Dawn, accidentally being left at the wheel of his Monte Carlo, shifting to neutral and ramming into a neighbor's van.

And then, there are the jokes. This combination came as Simpson announced the winner of a concert ticket contest:

"Rob Powell," Simpson began, "is going to be taking a guest . . . well . . . I guess he'll be taking a guest. I didn't really ask him. I don't even know if he knows anybody to take."

"He may not have any friends," inserted news director John Irving.

"I'm sure he can find somebody," said Simpson, "some lovely lady or half lovely lady--anything to take to the show! . . . I did hear him yell out, 'Louise, I won.' I don't know if she was just there for the morning or what."

"Uh oh, gotta watch that stuff."

"Boy, Rob's probably burning under the collar right now . . . Well, Rob and somebody will be joining us at the Capital Centre Saturday for the Shower of Stars. Hope I didn't get Rob in any trouble."

"Just kidding, Mrs. Powell, just kidding. . ."

Simpson may be free-wheeling about what he says on the air, but there's one thing he doesn't talk about, and has barred his deejays from talking about: the station's No. 1 rating.

"I don't believe in patting yourself on the back on the air," he says. "You shouldn't hype the audience up on yourself. If something goes wrong and you're No. 2 the next time, what happens then?"