Daniel Ortega, leader of Nicaragua's revolutionary leftist junta, took a most unrevolutionary campaign swing around the United States last week, trying to counter what he called the Reagan administration's "disinformation" effort against his government.

The trip here, laced with celebrities and full of media interviews and speeches, coincides with the vote expected Tuesday in Congress on funding Reagan's proposed aid to rebels fighting Ortega's government.

The barnstorming tour, which received mixed reviews, proved at least one thing: Ortega does not have the instincts of a U.S. politician.

In his stolid plod through four days of sunwashed living rooms and catered feasts, Ortega's stumping style oddly resembled that of his adversary, Secretary of State George P. Shultz. Ortega made the points he came to make in an off-the-cuff, low-droned version of what any campaign veteran would call "the speech."

Nevertheless, as with Shultz, every audience was rapt because of who Ortega is.

Ortega's transformation from the uniformed, podium-pounding comandante of Nicaragua's 1979 revolution into a sobersided, tweed-suited diplomat abroad was deliberate. It was part of a deadly serious continent-wide media blitz designed to humanize Nicaragua's leftist Sandinista government to U.S. voters.

The nine-day swing took Ortega, his poet wife, Rosario Murillo, and Foreign Minister Miguel D'Escoto -- and about 20 security and staff people -- through New York, Los Angeles, San Francisco and Boston, and is to end Tuesday night in Atlanta.

Ortega's effort is to be followed this week and next by "The National Town Meeting on Central America," a series of open discussions in six cities by a group of U.S. actors, politicians and activists, sponsored by the Los Angeles-based Committee of Concern for Central America.

All this has been timed to coincide not only with the peak of the U.S. presidential campaign but with crucial votes this week in Congress on President Reagan's aid program to anti-Sandinista rebels.

The idea, Ortega said in an interview, was to counter "the campaign of disinformation about Nicaragua" by the Reagan administration through meetings with opinion makers nationwide.

"The American people must put pressure on their government to change its policies toward Nicaragua," he told San Francisco Board of Supervisors member Nancy Walker at a private dinner. "It's the only way out."

The tour was a mixed success.

Los Angeles Mayor Thomas Bradley couldn't fit Ortega into his schedule and Vice Mayor Grace Montanez Davis gave the Nicaraguan leftist junta leader a welcoming certificate instead of the traditional keys to the city.

The Council on Foreign Relations in New York was "a tough, hostile audience" for Ortega's off-the-record speech, according to one who was there, and several Los Angeles Roman Catholic activists who wanted to ask Ortega about the church-state clash in Nicaragua said they were disappointed when he didn't mention the issue and allowed no questions at a church breakfast.

Some influential people were no-shows because the visit coincided with the Jewish High Holy Days. A Sunday gathering here that was to have been a star-studded extravaganza drew far fewer people than expected, apparently losing out to the San Diego Padres' victory over the Chicago Cubs in the final game of the National League baseball playoffs.

At most stops, Ortega appeared mainly to be "preaching to the converted," as former U.S. ambassador to Nepal Phillip Trumbull put it after a poolside lunch for academics, judges, attorneys and activists in the American Civil Liberties Union.

But lawyer Thomas McTerney, a venerable Los Angeles civil libertarian, said he had been skeptical but came away impressed with Ortega's defense of Nicaragua's position in regional peace talks. Foreign Minister D'Escoto, a Maryknoll priest, was boffo at the church breakfast and former presidential candidate Jesse L. Jackson called Ortega in San Francisco to offer encouragement and to arrange a meeting.

The Los Angeles Times, in a story about Ortega's visit, noted "a growing opposition movement to U.S. policies in Central America among members of the entertainment industry."

There was no doubt that Ortega's low-key manner was effective with those ready to listen. Mrs. George Slaff, wife of the liberal former mayor of Beverly Hills, was not fazed by the observation during a poolside breakfast news conference she held for Ortega that Marxists in his government would probably like to expropriate her wealth.

"A poor country's going to be harder on rich people than a rich one," she said, "but it's their business. I don't regard them as a threat to my way of life, or to the United States."

Ortega worked hard on the trip. As in any campaign, the schedule was brutal; the stops were chaotic with the press of reporters and eager crowds and anxious security men; and the mixups had elements of dark humor.

At the Los Angeles Children's Museum, Ortega's crush of people stopped to talk with a small group of children waiting in his path as if by arrangement. They all turned out to be deaf.

The overworked translator, Olga Sanbria of Nicaragua's United Nations office, was essential for Ortega, who speaks no English, but she was bumped briefly from Ortega's car when Robert Farrell, a member of the Council on Foreign Relations, was spontaneously invited to join in the tour. The men could not communicate.

Platoons of Secret Service agents and burly Los Angeles police officers on motorcycles shut down traffic for the motorcade so effectively that the Sandinistas' film crew missed at least one telegenic event and the U.S. media gave up the chase.

Security, according to Donald Casey of Agendas International, the New York public relations firm that organized the trip, was 8 on a scale of 1 to 10, if President Reagan gets a 10. Demonstrators for and against Nicaragua shouted and waved signs at some stops, and Los Angeles residents asked each other who was causing all the commotion.

"Somebody from Nicaragua," said a passenger on the plane to San Francisco. "Must be Duarte," responded his companion, naming the president of El Salvador.

Nicaragua pays Casey and his partner at Agendas International, Darryl Hunt, $54,000 every two months to fight that ignorance. They see Reagan's unlimited media access and joviality as their chief problem and Ortega's bicoastal sweep as a pale response.

"For a small Latin American country, this is the only way to fight back," Hunt said.

Ortega is willing, but he is no media natural. Hunt rejoiced openly last week when Ortega was seen smiling during a network television interview. "That's the first time I've seen him do it on camera; that's terrific," he exulted.

The company sends several Nicaraguan ministries and all nine directors of the Sandinista National Liberation Front a daily digest of 22 U.S. newspapers' coverage of Central America plus regular videotapes of the networks' stories, with evaluations and recommendations, Casey said.

Both he and Hunt were D'Escoto's seminary classmates 30 years ago, and they have the Sandinistas' full confidence. "We can talk tough to them and they believe us," Casey said.

He said Ortega had stopped condemning "Zionists" and restored newsprint to Nicaragua's only opposition daily newspaper after critical stories appeared in the American press.

Ortega's wife, Murillo, emerged as his secret weapon, turning skeptical faces into friendly ones during private talks at stop after stop. A famous poet of the resistance to dictator Anastasio Somoza long before marrying Ortega, she was instrumental in arranging the trip through her theater and literary contacts who founded the Committee of Concern.

Among those, she said, are singer Jackson Browne; director Bert Schneider and his wife, Greta; and producers Haskell Wexler, David Hanna and Daniel Selznick and Joan Keller Selznick. They have had "a multiplier effect," she said.

"We've grown in friends and in public support, even though many of these personalities don't identify totally with us; they have doubts but there's a basis of respect."

Murillo and Ortega have seven children. They met in 1974 after he read some of her poetry -- and sent her some of his -- during his seven years of imprisonment and torture by the Somoza regime.

It appeared to the media to be an obvious romantic tale, but the couple seems puzzled by the interest and both say they exchanged no single poem of significance.

Ortega, born into a family of anti-Somoza workers, was jailed for the first time when he was 14. His life has been little more than plots and politics and hatred for Somoza and his chief backer, the United States.

"It's true that as young people we were all involved against Somoza and we didn't differentiate between the North Americans who supported him and those who knew nothing about his politics. We saw all of them as evil," Ortega said. "With the passage of time we saw the situation goes deeper than that. . . . It is still hard to communicate with your government."

In his routine speech Ortega repeatedly made the same basic charges: The United States, pressing its covert war against Nicaragua without congressional approval, plans to escalate border fighting to a point where neighboring El Salvador, Honduras and Costa Rica ask for direct U.S. military intervention. Only U.S. citizen protests can stop a wider war in Central America.

State Department officials called this scenario "nonsense." The Nicaraguan presidential elections will be held Nov. 4; negotiations with opposition leader Arturo Cruz have ended because Cruz could not deliver the business side of his coalition.

Still, seven parties critical of the Sandinistas will take part and international observers, he maintained, will testify that it is free and fair. Reagan then will find it much harder to intervene against a duly elected government.

U.S. officials say that election plans are a farce and that Cruz is being excluded because he represents the only serious opposition. The real U.S. worry is not Soviet influence in Central America but that Nicaragua's survival might encourage other Latin American nations to become nationalistic and independent. "The United States was invading Nicaragua long before there was a Soviet Union," Ortega said.

U.S. officials say Cuban and Soviet advisers are directing Nicaragua's course and pose a direct threat to U.S. interests. The Reagan administration lies about the Nicaraguan reality, which is that no priests, journalists or critics have been killed at government hands and that a market economy continues.

Critics say Nicaragua persecutes church leaders, censors the press and harasses its critics while its economy is collapsing from mismanagement. The region's best hope for peace is the Contadora treaty proposed by Venezuela, Mexico, Panama and Colombia, which Nicaragua has accepted and the Reagan administration refuses to endorse.

The administration wants changes in the treaty to strengthen verification procedures.

At the final Los Angeles event, a fund-raiser for the Committee of Concern under a huge tent on the lush lawn of actors Robert Foxworth and Elizabeth Montgomery, Ortega was clearly as tired as his translator, making the same point three times.

But he invited the audience to visit Nicaragua and see for themselves. "Our revolution is not perfect, but we're trying to construct a better society," he said.

Raising a fist he added, to cheers: "If the United States commits the error of invading us, we know we will struggle with you at our side. Viva the people of the United States! Viva a free Nicaragua!"