Six defendants were arraigned yesterday in U.S. District Court in Alexandria in the $500,000 cocaine conspiracy and distribution case centering on Northern Virginia. There were arraigned on Tuesday and two are still at large.

Yesterday, Antonio L. Perdiz, Alfred D.C. McCoy, Llewyln Joseph Quander, Paulette Ashton, Wayne McNair Hargrove, and Marian Teresa Addair Starr pleaded innocent to the 20-count indicted handed up by a U.S. grand jury last week in Richmond.

Trial for the defendants was set for July 3, with motions scheduled to be argued on June 14.

Judge Oren R. Lewis yesterday said he had made available to defense attorneys more than 60 hours of tape recordings of a court-approved wire-tap on a phone located in an expensive Virginia high rise. The taped phone conversations detail nearly a dozen alleged "buys" of cocaine from the defendants by undercover District of Columbia police officers and U.S. Drug Enforcement Administration agents, Lewis said.

Also made available were 12 cartons of material seized in raids on two Northern Virginia locations, including telephones, scales, weights and measures, Lewis said.

Defense attorney R.Kenneth Mundy, who recently represented Prince George's County youth Terrence Johnson against charges that he murdered two police officers, yesterday appeared on behalf of McNair, Mundy complained that he could not prepare in five weeks to defend a case the prosecutors had been working on for more than 10 months, a motion Lewis rejected.