SAN FRANCISCO, Feb. 2 — The U.S. 9th Circuit Court of Appeals has upheld the conspiracy conviction of Sandra Good, the disciple of convicted mass murderer Charles Manson who once begged to join Manson in prison.

Miss Good was sentenced in March 1976 to 15 years in prison for conspiring to mail threatening letters and making telephone threats during interviews with three radio stations and a newspaper.

The mail threats were contained in 171 letters which were turned over to the FBI by a man who was supposed to mail them. Another 3,000 letters were found in the P Street apartment house Miss Good shared with Susan Murphy.

According to testimony at the Good-Murphy trial, the bulk of the letters was seized after Miss Good’s roommate, Lynette Fromme, was arrested for attempting to assassinate then President Ford during his September 1975 visit to the State Capitol.

In its ruling, the circuit court said “the evidence…was more than sufficient to support the jury’s verdict” of guilty. It rejected her claim that the letters were “mere warnings” and said the jury “could reasonably and obviously did take the letters and the telephone statements to be threats…”

During her sentencing Miss Good told U.S. District Judge Thomas J. Mac Bride “I cannot bear to be outside in your society…I want to be inside with my family.”

Throughout her remarks Miss Good made references to cult-leader Manson, the convicted mastermind of the 1969 Tate-LaBianca murders in Los Angeles and head of the so-called Manson family.