A tape of President John F. Kennedy's private conversations shows he was alternately demanding, diplomatic, exasperated and humble in his efforts to push for passage of the first limited nuclear test ban treaty.

On the eve of the 25th anniversary of the historic nuclear test ban treaty, the John F. Kennedy Library Thursday unveiled a tape and transcript of the Kennedy's behind-the-scenes campaign for congressional passage of the pact.Friday marked the 25th anniversary of Kennedy's signing of the treaty, which the Senate ratified 80-19 on Sept. 24, 1963. The treaty, also signed by the Soviet Union and Great Britain, barred nuclear testing in the atmosphere, on the ground and underwater.

Kennedy regularly recorded his telephone conversations in the White House, and the library claims to have most of the tapes. The 40-minute tape released Thursday was compiled from 13 White House conversations.

On the tape, Kennedy employs his powers of persuasion in telephone conversations with Cabinet members, senators and former President Harry Truman during the summer of 1963.

He insisted the Joint Chiefs of Staff give full support and was concerned that passage be bipartisan, said library historian Sheldon Stern.

"This is a revealing case study of how a president operates," Stern said. "It shows Kennedy in political, personal, constitutional and diplomatic dimensions. He's juggling all of these elements."

In a phone conversation with Secretary of State Dean Rusk on July 24, 1963, Kennedy was frustrated with senators hesistant to support the treaty.

"We got to hit the country while the country's hot. That's the only thing that makes any impression to these goddamned senators," Kennedy said.

"I would think that we don't want to wait just for their convenience. They'll move as the country moves," he said. "So, I think, we've got to go to the country while there's maximum interest."

Stern cited Kennedy's anger with Sen. Henry "Scoop" Jackson, D-Wash., who opposed the treaty, as an example of "how JFK's mindset changed in just three years from being a senator to being president.

"When we see him refer to `these goddamned senators,' we see him exasperated that a friend like Jackson would resist supporting him," Stern said.

In an Aug. 12, 1963, conversation with Sen. Mike Mansfield, D-Mont., Kennedy insisted the Joint Chiefs of Staff publicly support the treaty before testifying before a Senate subcommittee led by Sen. John Stennis, D-Miss.

"Yeah, what I'd like to do is get the chiefs on a public record before it can be leaked out . . . that the chiefs (have) grave reservations about this treaty. Which is what I'm afraid would come out of the Stennis committee."

One of the staunchest opponents of the treaty was Dr. Edward Teller, a physicist who helped create the hydrogen bomb.

In a conversation with Sen. J. William Fulbright, D-Ark., Kennedy displayed a characteristically dark sense of humor, expressing concern Teller's testimony would fuel Senate opposition.

"Well, there's no doubt that any man with complete conviction, particularly who's an expert, is bound to shake anybody who's got an open mind. That's the advantage of having a closed mind," Kennedy said.

Kennedy's predecessor, Dwight D. Eisenhower, had sought a limited test ban treaty, but his efforts were spoiled when a U-2 spy plane went down in the Soviet Union, Stern said. Eisenhower and his vice president, Richard Nixon, both supported the Kennedy treaty.

Kennedy also was concerned that former President Harry Truman support the treaty, and asked Truman on July 24, 1963, to review a copy of the document.

Truman called back July 26 to congratulate Kennedy on the treaty, saying, "I'm in complete agreement with what it provides. My goodness life, maybe we can save a total war with it. I think it's a wonderful thing."

Kennedy, obviously moved, responded: "Well, I appreciate that very much, Mr. president. That's very generous."