He told his son he wanted to buy the family a big farm. He told a business associate he was planning a major contribution to his church. He promised his mistress a yacht, a house in Georgetown, a trip to Rome.

It was clear to those who knew Ronald William Pelton that the 44-year-old computer analyst arrested last week on espionage charges wanted desperately to be able to fufill his big promises and show that he, a man who had known poverty and bankruptcy, could indeed be a financial success.

From interviews with friends and associates, a picture emerges of a hard-working man beset by self-doubt and the need to prove that he could do better than the dreary rental homes and broken-down cars that characterized his life style when he worked for the National Security Agency.

Intelligent and gifted at languages and music, he was determined "to make himself a success," said Brian MacAnanny, who has known Pelton for eight years and employed him as a boat salesman at Safford Yacht Sales in Annapolis this fall.

"He was just trying to achieve, always trying to achieve."

During the 14 years Pelton spent at the NSA, the biggest and most secret of U.S. intelligence agencies, the kind of success he wanted eluded him. He bought a plot of land in the rural town of Woodbine in Howard County, but he failed so miserably in his attempt to build a house there he had to declare bankruptcy -- a fact he hid from his parents, siblings and closest friends.

In the five years after he quit the NSA -- a period when he allegedly was selling secrets to the Soviets -- Pelton failed to become the international money broker and entrepreneur he hoped to be, though he presented that image to many associates.

He pretended to have an interest in at least two businesses and gave friends the impression he was making as much as $75,000 a year, but in fact he was a low-paid computer consultant. William J. Valois Sr., who employed Pelton at his landscaping firm for the last two years and at his health counseling center since the spring, said Pelton never made more than $21,000 a year -- $3,500 less than he was making when he told friends he was quitting the NSA to make more money.

Still, his circumstances improved dramatically after he left the intelligence agency. He went from a tumbledown shack in Howard County to maintaining two apartments in Dupont Circle. He went from struggling to clothe his children as nicely as their playmates to supporting a mistress with a taste for antiques and $200 evenings on the town.

His mistress, Ann, a former teen-age beauty queen from suburban Maryland who spoke on condition that her last name not be used, said that for the last year and a half, Pelton spent as much as $500 a week entertaining her, besides paying her rent of $500 a month and her bills.

"The money was always there," said the 29-year-old brunette while drinking vodka and grapefruit juice during an early afternoon interview.

She said Pelton, who promised her a trip to Europe on the night they met in a suburban Maryland bar, sometimes complained about the cost but was generally willing "to take care of me." She said he frequently took her to restaurants such as the Old Angler's Inn in Potomac and Duke Zeibert's for expensive dinners and his favorite drink -- Stolichnaya, the premier Russian vodka.

In addition to supporting her, she said, Pelton gave money to his estranged wife Judith -- whom he left with their two teen-aged children this summer -- and paid the rent for one of his two married daughters.

Ann said she believed that Pelton, a burly, sandy-haired man graying slightly at the temples, was well-off from two businesses that he told her he owned. Still, she said, they acknowledged that some of his money might not have been legitimately earned. She said she would ask Pelton: "Is it 'good money' or 'bad money'?" before they spent it.

Money, his friends say, was clearly his preoccupation. "He was interested in making a lot of it," said Paul Gayet, his former landlord.

Ann said that Pelton, the son of a television repairman, told her his parents were "always poor" and "he never wanted to be like them . . . . That was what drove him."

Normally quiet, Pelton would grow expansive on the topic of how he planned to pull off a major international money brokering deal that would bring in as much as $40,000 a day. Gayet said that for years Pelton told him that the deal was just around the corner.

He hid his failures, telling Ann he had to close out his interest in Valois' health center this fall when in fact Valois asked him to resign. He told numerous friends that he had been burned out of a house he built in Howard County when in fact he lost the partially erected structure because he could not make his mortgage payments.

Pelton was close-mouthed about his work at the NSA, where he had clearance to top secret and even more highly classified information, according to an FBI affidavit. "He never discussed his job," said Patricia Gardner, Pelton's stepsister who lives near Pelton's home town of Benton Harbor, Mich. "One time we asked, and he said that was something he could not discuss . . . . "

The government has not released a description of Pelton's duties at the NSA, but his military record shows that he was trained in highly sensitive areas.

He learned Russian at an Air Force language school in Bloomington, Ind., after graduating in the top quarter of his class in high school in Benton Harbor. He went on to become a cryptologic technician, working with sensitive government codes at a base in Pakistan and at the Air Force electrical warfare center in Texas.

According to Ann, Pelton grew to loathe his NSA job and complained to her that he was "a hunchback" from all the hours he spent at computer terminals.

After he left the NSA, Pelton met at least three times with KGB agents at Soviet embassies in Washington and Vienna and sold them super-secret material on methods that the United States uses to gather intelligence on the Soviet Union, according to an FBI affidavit.

According to the affidavit, Pelton received at least $15,000 on one of his trips to Vienna. Assistant FBI Director William Baker has said that KGB official Vitaly S. Yurchenko, who apparently defected to the United States in August and abruptly returned to the Soviet Union last month, gave investigators information that helped the FBI identify Pelton as a Soviet spy suspect.

The affidavit alleges that during an interview with FBI agents Nov. 24, Pelton admitted selling intelligence information to the Soviet Union. One of the agents testified at Pelton's bail hearing that Pelton was reluctant to talk to them about classified material until they assured him that they had the proper security clearance.

Pelton has not yet entered a plea. His court-appointed attorneys have indicated that they believe that the way agents handled their interview with Pelton could form the basis of an attack on the government's case.

Little in Pelton's manner or his life suggested to friends that he had a secret life. One friend, who asked not to be identified, said the Pelton he knows would have been frightened, not attracted, by the dangerous and secretive world of espionage.

"It just doesn't add up," said Pelton's sister, Patricia Gardner.

Ann said she had few hints of clandestine activity, but she noted one occasion when she and Pelton came "flying back" from Annapolis because he had to receive a secret telephone call at a Pizza Hut in Virginia. She said he said then that he was working undercover for the government.

She said that Pelton missed the call when they ran into car trouble and that he became "very upset. He said, 'Ann, that was our money and now we don't have it.' "

To those who ran into Pelton through his jobs or business ventures, he seemed to be a pleasant if rather colorless person who worked hard, liked to tell jokes and quoted the Bible frequently.

"He didn't give up like some people did," said Gardner. "When anybody else would have thrown in the checker, he wouldn't. He would play until you gave up."

He devoted substantial time to a church-run organization in downtown Washington that feeds homeless people, according to MacAnanny. Gardner said his wife Judith told her he played the organ for their church.

Ann said Pelton paid for meals for a friend of hers when she was evicted and was considering buying her an airline ticket so she could return to her parents.

In October, aware that he was being followed, Pelton suggested to Ann that changes were in store. She said that he told her that "there's not going to be any extra cash" anymore and suggested that they buy a yacht and leave the country.

Ann said Pelton, who is in the Anne Arundel Detention Center in Annapolis, has been calling her in recent days, pleading with her to wait for him.

He promised her, she said, that "it will all be over in a few months."