‘A Lot of Hubba-Hubba’ : WLT, A Radio Romance, <i> By Garrison Keillor (Viking: $21.95; 401 pp.) </i>

The people we fly over, those noncoastal heartland Nielsen families maddened by the wintry prairie winds, may produce more than their share of CEO’s and TV anchors, but they rarely see their visions affirmed on the national fantasy loop. Steven Spielberg’s suburbs and Stephen King’s small towns and Woody Allen’s cities seem never to be in the heart of the heart of the country. And the postmodern novelists keep missing the banal, yet dark dreams of Knut Hamsen and Theodore Dreiser.

This is why Garrison Keillor must be treated as a protected species. So sure and quirky and hip, who else could write: “Boys in the Midwest grow up without a word of praise, their parents fearful that a compliment might make them vain, and by the age of nineteen, they are riding so low their boat may be swamped by one small wave.”

Keillor’s sailor on this land-locked sea of life is Frank White, formerly Francis With, the Most Anonymous Person in the Class of 1947. He is still a teen-ager when he arrives in Minneapolis from a small town in North Dakota for a job in radio, this “warm thing that hums and reminds you of your mother.” The job was arranged by his uncle, a radio ad salesman, who prepares him for big-city life with such advice as: “For fooling around with, the girls with the flat chests are your hot babes . . . And a talker. You always want a woman with good chops on her. She’ll give you a lot of yap but she’ll give you a lot of hubba-hubba too.”

Keillor’s irresistibly delicious novel, “WLT: A Radio Romance,” uses radio as metaphor and gimmick in ways that are not new; in fact, the splicing of the real and broadcast lives of radio folk sounds tired. But in the chops of this essential storyteller, it is vivid and hilarious and sometimes, when it slyly alludes to the false values the media has sold us, it is downright subversive.

As Radio WLT dramatic characters like to say, “It’s awful hard to carry a full cap.” And rich folks on WLT series never seemed very happy, unless, like the Coopers of “Golden Years,” they had forsaken their city palace to run a rural diner and give away some of their millions whenever they heard a sad tale from a worthy soul.

Keillor’s precisely detailed, yet woolly saga begins in 1926, when Roy and Ray Soderbjerg, hoping to become the sandwich kings of south Minneapolis, open a restaurant in a Lutheran mortuary that had once been the Pillsbury Mansion. To boost lagging business, they buy a radio license for $25 and broadcast programs from the dining room. Their station is called WLT (With Lettuce and Tomato) and from its first instant on the air it seizes its audience, thanks to “Dad” Benson’s voice, “that warm dry Minnesota voice with a slight burr, a little catch in it, a little hesitation that got the listener leaning forward” into a wave of “false friendship. That was radio in a nutshell. Announcers laying on the charm to sell you hair tonic.”

The Soderbjergs are shocked by their instant success. Would-be advertisers fight for air time. Dutch Brand coffee wants a show with lots of coffee drinking so Dad created “Friendly Neighbor” in which he and his family eat lunch and gossiped.

Other shows follow: “Scripture Nuggets” and “Current Events” and “Avis Burnette, Small Town Librarian.” One of the Radio Cowgirls, Patsy Konopka, a pretty theosophist so “sick of yodeling I could spit,” talks Ray Soderbjerg, the old “bed-dancer,” into letting her create shows. She is soon grinding out 100 pages a day and fantasizing about the young man in the apartment upstairs, Frank White. She is too tired to try to meet him; she can only imagine him in her scripts.

Let’s pause for a word of warning: Those who love Garrison Keillor as that warm dry radio voice restricted by broadcast codes may be delighted or appalled by the relentless sex and scatology of this book. It’s dirty, in that old bathroom, sniggering way, which I found simply guffawful.

In fact, there is something so determinedly adolescent about the endless eating, farting and sex that it seems like a returning art form. Keillor’s finest set piece is a gospel-church tour with the rowdy Shepherd Boys. It puts the “fun in fundamentalism” and may be the greatest literary bus trip since the “Electric Kool-Aid Acid Test.” And much funnier.

Keillor’s easy, conversational style occasionally cloys, and while the meandering plot has a plan, he loses interesting characters along the way. The ending is abrupt. But those are criticisms of the book I would have had him write. The one he did write is a satisfying romp with a shrewd yarnmaster who can make you howl. The Midwest sensibility, compassionate and knowing, yet unsentimental, is also worth the price of admission.

And the metaphor holds. The ultimate, cheesy triumph of Frank White comes in television. That gorgeous and demented child of radio is perfectly described early on: “They will invent something. It’ll have the same effect as bourbon but it won’t give you headaches or upset the stomach, so it’ll be used even by the kiddos. It’ll earn gazillions.”