TEN YEARS ago today, an experiment in daily electronics journalism got off to a shaky start out of the year-old National Public Radio studio housed in the basement of an M Street office building; on that same May day, thousands of antiwar demonstrators tried to close down Washington, and "All Things Considered" spent 30 of its first 90 minutes broadcasting from the heart of the insurrection.

In the decade since, the daily news and public affairs program has evolved from one of the best kept secrets of the airwaves to an aural sanctuary for close to 5 million listeners across the country who tune in to the show's provocative blend of hard news, life-style features, commentary, interviews and satire. Its perceptive, in-depth coverage extends not only to the stories behind the headlines, but to the wide range of human experience.

When this country normalized relations with Red China, ATC devoted a 30-minute segment to asking China experts around the world, "What difference has it made that we haven't had formal relations with Red China for the last 30 years?" The range of answers included American's not becoming involved in wars with Vietnam and Korea, to suggestions of a less hard-line communism had postwar Chinese politics been tempered by Western influences.

When Polish students took over the university at Gdansk, ATC got the phone number for the registrar's office, patched on through to an English-speaking student involved in the seizure and once again "went right into the heart of the question," according to executive producer Chris Koch. "We can reach very far in our coverage. Radio is such a quick medium and it's so inexpensive. Our basic technology in foreign policy is the telephone."

A Kansas City art teacher sent ATC a 15-minute tape in which he went door-to-door asking people a question that would rarely be heard elsewhere: "What do you know after all these years?" There have also been segments on a husband-calling contest in the Midwest and a rattlesnake roundup in Texas. "We don't just have to hit the highlights of major stories," says Kock. The 90-minute weekday and 60-minute weekend formats "give us the luxury of going long, with anywhere from 15 to 23 stories. We can do features that reveal attitude and personality and regional differences but don't necessarily relate to breaking news."

How to segments have ranged from "how to survive in Siberia" and "how to cure hiccups" to "how to milk a camel"; in the midst of incisive interviews and serious-minded features, there has always been time for such pieces of whimsy as ATC host Susan Stamberg and science reporter Ira Flatow sitting in a dark studio munching wintergreen lifesavers to see if they spark when bitten in two. (They do.) It is these human, accessible stories that provide the fascinating variety to each day's broadcasts.

Commentary from such diverse voices as Daniel Schorr, macabre cartoonist Gahan Wilson, Heywood Hale Broun, the satirical Duck's Breath Mystery Theater and the fine Indian novelists N. Scott Momaday fulfills ATC's unflagging interest in informing rather that just reporting. As Stamberg says, "It's not so important to break the news as to get it right." These commentators provide clues, not answers. One of ATC's charms is that it makes a point of exploring possibly diverse answers to questions raised by the events of the day.

In the inconoclastic spirit that the Wall Street Journal calls "biting the hand that funds it", ATC has held "name that warplane" contests for the Pentagon, produced a TV game show parody to explain IRS policies, and created an opera bouffe ("Ratio Interesso") to describe the rise in interest rates. At one point, the CIA asked ATC to suppress a story on the sunken Soviet nuclear sub Glomar, ATC reported both its original story and the CIA request.

Political and economics reporters and analysts like Linda Wertheimer, Cokie Roberts, Pauline Frederick, Nina Totenberg and Robert Krulwich have not only set high standards seldom matched by major network compatriots, they have turned ATC and the more recent "Morning Edition" into a haven for serious broadcast news. Many of ATC's central core of 21 reporters, editors and producers come from a print background, a factor that has allowed the show to graft the traditional depth of print onto the immediacy of radio and television to two-minute news capsules and redundant all-news formats. ATC has won so many awards that it's little wonder that Fred Friendly, former president of CBS News, has said, "It towers over the competition in commercial radio and television."

In 1971, when ATC's first producer, Bill Siemering, outlined goals for NPR's flagship national program, there was an almost naive optimism about such things as "humanizing institutions. . . breaking the density of heavy news." Yet that's exactly what the program has done. "It's not just a headline service," says co-host Sanford Ungar. "It says that there are things happening in our lives it's okay to laugh about."

ATC has put the "public" back in public radio and become a vax populi of the airwaves. Though it is a team effort, one person has come to symbolize the show's ongoing appeal: Susan Stamberg, who has anchored ATC for more than nine years, making her the first woman to anchor a nightly news program in America. Stamberg, 42, hasn't been on the air since November because she's been writing a book for Pantheon on ATC's first decade; she's expected to return to the air in early June.

In her cluttered office, she looses a trademark laugh as she points to a stack of manuscript papers: "It's four inches tall and weighs four ounces more than my son did when he was born," she says in a voice unique in radio -- a semi-nasal New York accent freely punctuated by laughs, giggles and near visible incredulity at the things some people try to get away with in interviews. Its often conspiratorial emphasis is anchored by a natural effervescence that's hard to resist.

In person, Stamberg's a gregarious earth-mother with a grin that barely holds in the same delightful sense of discovery she transmits through the microphone. One of Stamberg's not-so-secret qualities centers on her interview technique. She is agressively conversational, blessed with the kind of chatty informality one might expect at a high-brow cocktail party that's run out of liquor but not out of ideas. "The art of conversation is dying in this country," Stamberg feels, "and there's no place to hear it. Many interviewers don't listen to answers, to what's being said. I like to scramble up with a person, get in their rhythm. What you've got then is a conversation, not an interview."

Stamberg generally avoids politicians or economists ("they'll never tell me anything they wouldn't tell 12 other people"), though she was one of the few media figures to get John Erlichman to talk about Watergate. She also earned the enviable task of hosting a two-hour call-in show with President Carter in 1979. The 42-year-old Stamberg admits, however, to greater satisfaction from a September interview with "a 9-year-old kid in New Haven, Benjamin Alsop, who was going bluefish fishing in the Connecticut River for the first time in his life. He was so open and genuine and wonderful about it. . . it was really thrilling to me."

A liberal arts graduate from Bernard College, Stamberg moved to Washington when her husband took a job with AID. She learned radio production at American University's WAMU, moving from producer to program director to general manager at the station. After a family stint in India, she returned to Washington and hooked up with National Public Radio, which has been almost an afterthought to the television oriented Corporation for Public Broadcasting act. Stamberg started out as a tape editor, moved into reporting and finally filled in for host Mike Waters in 1972; she's been on ever since with a variety of co-hosts including Bob Edwards, who moved to "Morning Edition" in 1979, and Sanford Ungar, who began co-hosting 14 months ago. The Staff

Sanford Ungar, 35, an author and former reporter for UPI and The Washington Post and managing editor of Foreign Policy magazine, also hosts NPR's international affairs series, "Communique." He is in many ways typical of the "best and the brightest" philosophy brought to NPR when Frank Mankiewicz became its president in 1977. Mankiewicz lobbied for increased funds; getting them, he raised salaries, hired reporters, bureau chiefs and content editors; he also upgraded the broadcasting technology to state-of-the-art. Mankiewicz "allowed for the proper support," says Stamberg. "He understood the concept of a daily magazine. There was no tradition of journalism or news presence in public radio before ATC. Bill Siemering had wanted it to be the finest journalism available; Frank understood and it sure made a difference."

The ATC staff is young, independent, smart. The daily meetings at which they discuss the flow of stories for each day's program are a clutter of newspapers, magazines and filled-in notepads from which they pull story ideas and try to find reporters and commentators who will provide insights and seek motivations rather than just turning in "quick and dirty" news. "Our meetings are modeled on Lou Grant!" Stamberg suggests.

From the 10 o'clock morning meeting until air time at 5 p.m., the staff will phone, edit, write copy, collate stories from a dozen reporters all over the country and generally move in a controlled frenzy trying to make everything fit smoothly while maintaining an intelligent tempo. In a world of constantly changing road maps where lives are lived in 15-minute segments, things can get out of hand. One day a producer and an editor rushing from different ends of the newsroom collided so hard they were both knocked out cold.

Two charges have spurred ATC's phenomenal popularity in recent years. Over the years, there have been accusations that ATC reflected an East Coast bias, and executive producer Koch admits that improvements need to be made in the program's representation of the rest of the country through "regional features that give a sense of the ordinary, daily life of people." Two years ago, NPR instituted a satellite that not only provided a remarkably clear signal to the 243 NPR stations around the country, but also made it easier for the Washington production center to work with outlying member stations.

Concurrently, ATC formed an acquisitions unit with editorial discretion and control over pieces coming in from member stations and freelancers. "We've had consistent editing for a year now," beams Koch. "Reporters who were good are now very good because they've been subjected to a tough editorial process. It's dramatically increased our national input."

Over 10 years, people have become so used to ATC's excellence that many take it for granted. The plethora of awards, including this year's prestigious Alfred I. du Pont-Columbia University Award for ATC's "daily commitment to creative and resourceful reporting," stand as solid evidence in ATC's biggest challenge: the cutback in government funding for NPR.

Before NPR came into existence, public radio in America had no identity; it was a weak system generally tied to educational institutions. Eleven years later, it may still be struggling for funds and recognition, but its achievements have been remarkable. Look at ATC alone: the program had no role models when it started, but a strong case could be made that programs such as "20/20," Charles Kuralt's "Sunday Morning" and ABC's "Nightline" have been inspired by ATC.

One thing is for certain. A great many people have come to rely on ATC as a balanced source of "information of consequence," as Bill Siemering hoped when he set the program's goals. Combined with "morning Edition," ATC provides three and a half hours of news, a presence exceeded only by all-news formats; it's all done on a combined annual budget of $3.2 million, a ridiculously low figure, considering all things.

In the end, it's the diversity of human experience that comes shining through with each daily broadcast. Stamberg pinpoints ATC's values in relationship to traditional news approaches. "Take Henry VIII. You may know the dates, but you really don't know anything. You don't know how people lived at the time, what their values were, what they considered beautiful, how they interacted with one another. I feel that way about most fact-and-event reporting. We're after the meaning of the news, the impliations behind it, the ideas that lead to events. I can't imagine doing anything else."

[Tomorrow's ATC broadcast will include a special 30-minute segment featuring some of the most popular stories from the program's first decade, as well as comments from current and past staff members. The show is heard locally on WAMU-FM (weekdays at 6:30 p.m., weekends at 5 p.m.) and WETA-FM (weekdays only at 5 p.m.)]