He's been called folksy and corny and admits to being a Pollyanna, but nearly a million New Yorkers, many of them sophisticates, welcome John A. Gambling into their bedrooms, bathrooms and kitchens every morning. Celebrating his 25th anniversary this year with radio station WOR, John A., 54, is now the formidable patriarch of a unique radio dynasty that began at the station with his father, John B., in 1925 and for the past seven years has included his son, John R. Rambling With Gambling, John A.'s show, airs six days a week in the prime 5 to 10 a.m. slot, and his effortless blab has preceded and/or outlasted disco, ethnic and almost every other kind of programming. In a city where some 50 stations vie for listeners, he remains near the top in the ratings, and his million-dollar-a-year salary makes him one of the highest-paid radio personalities.

Just what makes John A. Gambling so successful? The answers are consistent and admiring. "When I first got here 10 years ago," says his consumer affairs reporter, Joan Hamburg, "I didn't get why he was so popular. Then I began to understand. He's like his listeners. He's Everyman. He's not perfect, he's a little fat, he's got problems with his children. But he loves his wife and always remembers birthdays." Don Criqui, Gambling's sports announcer for 19 years, says, "With the world changing, he's like the Rock of Gibraltar. You know what you're going to get every morning." Even his WNBC rival, hyperkinetic Don Imus, turns his negatives into a positive: "There's not much not to like about John."

Gambling acknowledges he's not a boat rocker. "I believe the morning is bad enough as it is," he says. "I don't want to talk about anything that's going to offend anyone. What's the point?" Though his show is basically information, offering frequent updates of the news, weather, sports and traffic, he still evokes a small-town family feeling in his program. Church dinners, school fairs and new restaurant openings are never beneath attention. His listeners, who have grown up with tales about his wife, Sally, and their three children, view him as a friend. His fans don't ask for his autograph; they invite him over for lunch.

Sixty years ago Gambling's father was a young English-born radio technician with WOR. One serendipitous day he pinch-hit for the host of a calisthenics program, and, when hundreds of callers praised his baritone voice, John B. inherited the show. He gradually turned it into a music and information program called Gambling's Musical Clock. His 30th-anniversary show from Madison Square Garden drew more than 25,000 fans, including Mayor Robert F. Wagner.

By the time John B. retired in 1959 after 34 years, he had set the standard for morning talk-and-news programming. His only child took over. "He taught me you've got to have respect for the people listening to you," John A. says. "They are real, warm, intelligent human beings. You're not talking to them, but with them."

Though John A. had made his radio debut at age 4, singing a Christmas carol on his father's show, he did not plan on following in his father's airwaves. He grew up on Manhattan's West Side, where his mother, Rita, was a housewife, and entered Dartmouth as a pre-med student. "After flunking freshman chemistry, it seemed a pretty good time to forget about being a surgeon," he says. During his junior year he married his high school sweetheart, Sally Loppacker, and began working for the school radio station. After graduating with a B.A. in drama, he applied for radio jobs. WOR was his only offer, and charges of nepotism were inevitable. "Sure it rankled and hurt when people said I got the job because of my father," he admits.

Though John B. died in 1974, there are still two Gamblings at WOR. John A.'s son, John R., 34, joined the station in 1978, working several years as co-host on Good Afternoon, New York, a celebrity-interview show. John R. first put in five years of broadcasting elsewhere, but he too faced nepotism charges. "It makes you work three times as hard," he says. The Gamblings' daughters, Ann, 32, a bond trader, and Sarah, 25, who's in retailing, have tuned out to radio.

Aside from the microphone, John A. admits, "there's nothing in the world that would make me happier than to run my family's lives, which they firmly forbid me to do." His children concur but are still frequent visitors to their parents' spacious, art-filled Manhattan co-op. Sally says she has never missed her husband's show, and she also shares his passion for boats. The couple just returned from a two-week vacation to Florida aboard their 42-foot trawler.

John A. contemplates retiring in five years, and it's no secret that John R. is being groomed as his successor. This January he left his afternoon program to join his father's show, where he serves as co-anchor. The Gambling succession may not stop there. John R.'s 4-year-old twins, Andrew John and Bradley John, have already been on the air with their dad, and his wife, Wendy, is expecting another baby. At this rate, the Gamblings may just keep on rambling indefinitely.