The ex-wife of admitted spy John Anthony Walker Jr. testified today that she told Jerry Alfred Whitworth as early as 1973 that she knew her husband "was recruiting him to spy" and warned him that John Walker "couldn't be trusted."

In an emotional 45 minutes of testimony about her life as the wife of a spy for the Soviet Union, Barbara Joy Crowley Walker said John Walker gave her "two black eyes" when she accused him of spying, told of accompanying him on "drops" of classified information to prove "how much I cared," and described years of agonizing over whether to turn her husband in.

Testifying at Whitworth's espionage trial, Barbara Walker said she assured Whitworth shortly before her 1976 divorce from John Walker that she had no plans to expose her husband.

"He asked me if I would ever turn him [Walker] in and I said I didn't want revenge," Barbara Walker said.

Walker, 48, a store clerk in West Dennis, Mass., wept softly through much of her testimony and at one point ran out of the courtroom, saying, "I'm sorry, I'm getting sick to my stomach."

She testified that in a telephone conversation in April 1985 -- the month before John Walker's arrest -- her ex-husband bragged that he would become a celebrity if she exposed him and assured her that their only son, Navy Seaman Michael Lance Walker, was not involved in the ring.

Michael Walker, 23, who bears a striking resemblance to his mother, pleaded guilty to espionage along with his father in federal court in Baltimore last Oct. 28.

In a press conference later with her attorney, J. Albert Johnson, Barbara Walker said she would not have tipped off the FBI to John Walker's activities in November 1984 if she had known her son was spying.

"I still cannot deal with my son being arrested," she said. "It's hard to talk about."

Barbara Walker testified that when she confided John Walker's espionage activities to her brother-in-law, Arthur James Walker, he told her in 1968 that he had been involved in espionage while stationed at Groton, Conn.

Arthur Walker was convicted of espionage last August. John Walker testified last week that his brother joined the spy ring in 1980.

Barbara Walker described confronting her husband with evidence about his espionage activity in 1968, the year he started spying, after going through his desk.

John Walker, she said, "struck me in the face two or three times" and gave her "two black eyes."

"Did you tell the authorities?" defense lawyer Tony Tamburello asked on cross-examination.

"I thought about it," Walker said, choking back sobs. "I tried to call the FBI but I couldn't."

Walker said she tried to call the FBI several other times in later years. One time, she said, she got through but hung up when she was informed that the FBI could not guarantee "protection" for a person who exposed a spy.

She said that a key concern was for the well-being of their children. The Walkers had four children during their 19 years of marriage. Barbara Walker was given immunity from prosecution for her testimony today.

In testifying over the last two weeks against Whitworth, his former Navy colleague and best friend, John Walker repeatedly characterized his ex-wife as an alcoholic "snitch" and denied hitting her. In her testimony today, Barbara Walker said she did not start drinking heavily until after she discovered that her husband was a spy.

Barbara Walker's testimony differed from her former husband's on several other points. Most notably, John Walker testified that he directly broached the subject of spying with Whitworth in 1974 after several years of testing whether his friend had enough "larceny in his heart." Barbara Walker said she and Whitworth discussed John Walker's recruitment of Whitworth in 1973.

Whitworth, 46, a retired Navy communications specialist, is charged with conspiring with Walker to spy for the Soviets from 1974 until Walker's arrest last May. Whitworth allegedly received $332,000 for his role in what authorities have called the most damaging espionage ring in decades.

Under questioning by Assistant U.S. Attorney Leida B. Schoggen, Barbara Walker said that during her 1973 discussion, Whitworth said he hesitated to become a spy "because John bragged too much and he didn't trust him. I said something to the effect that he couldn't be trusted."

When Whitworth visited her at her home in Norfolk in 1976, Walker said, "Jerry said he didn't trust John and I said I didn't blame him." She said she related "some very negative things" John Walker had told her about the man he described in testimony as his "best friend" -- that Whitworth was bisexual, used drugs, and was "involved with a very young teen-ager."

Asked by Tamburello if she believed that, Barbara Walker said, "I considered the possibility."

"Is it not true that Mr. Walker lied a lot?" Tamburello asked.

"He was known to tell a few," she replied.

She said that "in the beginning" she would iron the money Walker received from the Soviets to flatten it out because it was delivered in tightly rolled packages.

Walker said she "suggested" to her husband that she accompany him on a drop in 1968, several weeks after she discovered he was a spy, because "I wanted him to know how much I cared."

She described driving a circuitous route in the Fairfax County countryside, once for practice and once, after dark, to drop a bag disguised as trash and pick up a package of money.

John Walker was arrested May 20, the day after FBI agents saw him drop a similarly disguised package full of classified documents from the aircraft carrier USS Nimitz, where Michael Walker was stationed, at a remote site in rural Montomery County.

Barbara Walker told of flying to the East Coast from California for another drop in 1974, when John Walker was serving on the USS Niagara Falls.

John Walker picked up about $35,000, she said, and before the return flight to California "asked me to tape a good part of the money to my body and inside the lining of my coat, so I did."

John Walker insisted in his testimony that Barbara Walker accompanied him only on one drop and that her memory was fogged by alcohol.

When John Walker was transferred back to Norfolk and was driving across the country with his family, he made another drop, Barbara Walker testified. "I was very angry," she said. "My children were there and I couldn't believe he was doing it." John Walker, she said, made the drop anyway.

At the press conference, Walker said, "Of course I have regrets" about calling the FBI. "But I knew it was something I had to do. I lived with this for a long time and it was just something I couldn't live with anymore."

Asked to respond to her husband's characterizations of her, Walker said, "Of course I care how he feels. I was married to the man for 19 years. He's the father of my children."

Asked why she thought her ex-husband started spying, Walker said, "John had a great deal of difficulty facing problems. He just took the path of least resistance" out of his financial problems.