One thousand miles to the northwest of DeLaind, Fla., the Army plots its courtship of the Hills and Duplers and Alls and Elmores of Main Street America with the ardor of an unrelenting suitor.

The headquarters for the U.S. Army Recruiting Command -- USAREC in the inevitable acronym -- is in this placid warren of refurbished cavalry stables wedged against Lake Michigan, north of Chicago. The advertising and marketing campaigns hatched here are as sophisticated as the peddling of any product in America.

As the Army ponders its one-year market plan and five-year strategic plan, the tactics of other sellers, such as Coca-Cola and Allstate Insurance, are studied for clues to cracking the youth market.

In 1984, the Army will spend $62 million to advertise itself, a major component of the $4,500 average cost to recruit one soldier. It costs another $11,700, on average, to train that soldier.

"In Marketing I, the first thing they tell you is to find a product that everybody needs and wants and, if you can find a way to do it a little better, the world will beat a path to your door," said Tom Evans, USAREC's deputy director of advertising and sales promotion. "We have almost exactly the opposite situation. . . . I draw the analogy to telling the leading American bicycle manufacturers that they've got to sell four times as many bicycles next year."

During the first six months of last year, when the Army bought 152 30-second television spots, it cost an estimated $54.29 "per thousand impressions" among viewers. That compares favorably to the $63 for Budweiser advertising -- 624 ads -- and $67.30 for McDonald's -- 902 ads -- Evans said.

To keep a "top-of-the-mind awareness," in the jargon of Madison Avenue, the television message of Army opportunities is reinforced with radio spots because "there's a psychological theory that goes back to the 19th century which says people start to forget the message pretty quickly unless it gets reinforced," Evans added.

The evolution of the Army's advertising began after the abolition of the draft with the theme, "Today's Army Wants to Join You."

Evans said the campaign "was particularly appropriate because in the early '70s the Army was on the defensive. But people in the Army went bananas. They hated it because they thought it was demeaning to the Army to go begging. It was an advertising success, but the Army establishment just couldn't accept it."

Another early campaign asked, "Why Should the Army Be Easy, Life Isn't?"

In the modern Army, the ads proclaimed, "the Cavalry flies, the Infantry rides and the Artillery can hit a fly in the eye 15 miles away. It's a printed-circuit, solid-state computerized Army." The text originally read 35 miles until the artillery protested that it wasn't that good.

Another ad, which proclaimed, "In Europe You're on Duty 24 Hours a Day but the Rest of the Time Is Your Own," was scrubbed after recruiters grumbled that their job was hard enough without implying that the Army was a kind of American Gulag.

The highly successful "Be All You Can Be" campaign began in January 1981, after a year of developpment by the Army's longtime New York advertising agency, N.W. Ayer.

After evaluating a complex series of attitude studies and survey groups, the Army decided it had an image problem because it was viewed as stodgy and pedestrian, especially when contrasted with the high-technology, modern-skills image projected by the other services. So the Army spruced up and preened as a creature of the 21st century.

"This isn't reality, it's advertising," Evans said. "Some people say you ought to tell it like it is, warts and all. But that's not realistic. . . . If you're even going to attract their attention, it's got to be punchy and a little bit glamourous. There would be an ethical problem with that if they joined the Army just on the basis of the ads. But if that was the case, they'd be too dumb for us to want them anyway."

Above Evans' head as he spoke was a large poster, based on British World War I recruiting ads, depicting Uncle Sam with his billy goat beard, commanding, "I Want You for the U.S. Army."

"It's off-strategy, as we say in the business," Evans said, shrugging at the old poster. "It has an honorable place in the archives, but it doesn't really fit with the modern, high-tech image we're trying to project."

Outside the cramped Army recruiting office on New York Street in DeLand is the very same larger-than-life mug of Uncle Sam. It may be off-strategy at Fort Sheridan, but it's on the street in central Florida.

Beyond the DeLand city limits, a stone's throw from Bethlehem Baptist Church, Jerome Harris sits in the rude, two-room shack he shares with his grandparents and two others. A rooster crows on the back porch and dust boils in the road outside.

The house is rickety enough that when the Army recruiter, Sgt. Ray Hessler, arrived one night in his finest dress blue uniform to woo Harris' guardians, he crashed through a hole in the kitchen floor.

Harris says the Army's ads "don't mean nothing to me." As a 17-year-old poor black, the military is his ticket out and he doesn't need any slick talk about high tech.

Harris has signed on as a 12 Charlie, a bridge crew member, and after agreeing to join the Army, his school grades soared from mediocre to outstanding. To prepare for boot camp, he has been running three miles a day and doing 50 pushups. He, too, like Ron Logan, is ready to be all he can be.

"The reason I'm going in is because there ain't nothing to do around here," he said. "It's pretty dull. No good jobs. I'm ready."