Twenty-five years after they inadvertently transformed American TV forever, the men behind the scenes of the first Nixon-Kennedy presidential debate emerged tonight to reminisce about the great event.

At a black-tie dinner in Studio One at CBS' Chicago station, WBBM, the very studio where the debate occurred, the memories were fond and still full of surprises.

Those here included Richard M. Nixon's press secretary at the time, Herb B. Klein; veteran CBS producer Don Hewitt, who directed the Great Debate; and Oliver Treyz, former chief of the ABC network.

In addition, Sander Vanocur, one of the four newsmen who tossed questions to the candidates at the pivotal first-ever televised presidential debate on Sept. 26, 1960, was on hand.

These men and others told how the show came about, and what happened as the hour that attracted about 70 million American viewers unfolded.

Treyz recalled that he noticed Nixon looked somewhat ill when he showed up at the studio before the debate. "How are you feeling?" he recalled asking Nixon.

"I have a temperature of 102," Nixon replied.

Nixon told Treyz he was taking a drug, tetracycline, for his illness.

Treyz suggested the debate be postponed. He recalled Nixon saying something like, "No, people will think I'm chicken." And the debate went on.

The confrontation 25 years ago is a founding episode in the dawning Age of Communication. By most measures, Nixon won the most debating points. But Kennedy won the show, a victory he owed as much to his mastery of show business details as to the substance of his answers.

In opening remarks tonight, Newton Minow Jr., Kennedy's FCC chairman, observed that that first debate "would change the world" and had led to the staging of debates by presidential candidates in each of the past three elections. Spontaneous unrehearsed debate by national candidates "is now adopted by other nations and other cultures" around the globe, Minow said. He urged the audience to "use this gift to help preserve" American democracy.

Hewitt, now executive producer of CBS' "60 Minutes," recalled that as frantic last-minute preparations were going on for the debate, he suddenly encountered John Kennedy, "this tall New England guy who arrived out of nowhere." He said he turned to Nixon and introduced the two men, saying, "I assume you two guys know each other."

He recalled how Nixon turned down an offer by Hewitt to have makeup applied by the CBS makeup artist, Frances Arvold.

Hewitt then said he encountered Nixon again three years later, a few days after Kennedy's assassination. Nixon was about to go on TV in a tribute to the slain president. Noticing that Nixon was being made up, Hewitt said, "Mr. Nixon, if you'd have let Frannie make you up then, you might have been president now." Nixon replied, "Yeah, and I might have been dead now too," Hewitt recounted.

Hewitt then went on to recommend that news reporters not be chosen to ask questions in future presidential debates. He said it would be better if politicians of each party posed the questions to their adversaries. The drawback of having journalists ask the questions, he said, is that they are thinking chiefly of "What can I say that will make me look good, and not partisan?" He proposed that future debates take place before joint sessions of Congress and that the media participate by reporting the event, not arranging it.

To a burst of applause from an audience composed mostly of Chicago TV journalists and advertisers, Hewitt said, "I don't think America should pick its presidents by their television performances."

Before the dinner, Vanocur, now with ABC, said that when he agreed to be a panel member, he had little notion that he would be participating in a historic event. He recalled having no clear sense of who had won the debate. "I didn't see what the nation saw on television," Vanocur said. "I was there."

The sponsor and beneficiary of the evening is the Museum of Broadcast Communications, recently formed to preserve, catalogue and display the history of the Windy City's radio, television and broadcast advertising industries.

Reams have been written about the Meaning of the first Kennedy-Nixon debate (there were four in all), which made the tube not just a reporter of but a participant in presidential politics. But no historic account captures the freshness of that encounter. Seen again via a flawless black and white tape, the debate remains one of the most riveting 60 minutes of television ever beamed into the ether.

The excitement comes partly from the miracle of reliving that crucial, long-ago moment. But there is something else that makes watching the debate a revelatory experience: Regardless of your politics, you can see why Nixon lost and Kennedy won.

There is Nixon, initially looking better than history would lead you to believe. Not handsome, yet his dark hair, prominent eyebrows and slightly tense expression convey knowledge, authority.

But wait a minute! That suit!

Light gray on the tube, its collar hangs like a cowl. This garment shows every wrinkle from wrist to pants cuff. Max the cobbler must have stitched it together around 1948. The face looks pasty. This guy is our vice president? And he looks like that?

There is Kennedy to the left of the screen. Strange accent, metallic voice.

But wait a minute! That suit!

Dark blue, maybe a pin stripe, not a wrinkle anywhere. It elegantly chisels his torso into a slender, athletic figure. The face is tanned, the eyes gleam with an astonishing hooded intensity that dazzles the viewer's retina.

This guy wants to be president? Not bad . . .