Herbert Springer, 47 once a prosperous D.C. businessman, was sentenced to a minimum of 18 months in prison yesterday for conspiracy to murder his estranged life and for soliciting a "hit man" to do the job.

Judge Nicholas S. Nunzio act the penalty despite a lengthy statement by defense at the time he began by a defense attorney that Springer has a manic depressive at the time he began the conspiracy in January, 1976.

A co-defendant, Ralph Turner, 36, was given a one-year prison term for his part in the scheme.

Turner had been offered immunity in the case by U.S. prosecutors in return for his testimony against Springer. Instead, he chose to go to trial. Both Spinger and Turner faced maximum sentences of 10 years in prison.

According to testimony in their trial last month, Springer told several friends he would pay $30,000 to get his estranged wife, Sally, "off my back." Among the friends was Turner.

Turner contacted a paroled convict named Clarence W. MacFarland, 43. MacFarland reported thi to the FBI and the FBI told the D.C. police department.

Clayton L. Bagley, a D.C. homicide detective, was assigned to investigate the situation. Posing as a "hit man," or murderer for hire, he offered his services to Springer. After convincing Springer that he had murdered Mrs. Springer Bagley took a $100 payment from him against a total fee for the job $10,000.

Springer testified that he had been "only playing a game with Bagley.

Members of the Springer and Turner families wept when the prison terms were announced.

Judge Nunzio suggested that Springer might serve his sentence at the federal detention facility in Springfield, Mo., where psychiatric help is available.