September 15, 1983

The chairman of a House subcommittee said yesterday that next Monday's hearing on allegations of police brutality against black New Yorkers would be held in a state armory in Harlem. Mayor Koch immediately responded that he would not attend. The Mayor said the ''cavernous atmosphere'' of the armory was not an appropriate place to hold a Congressional hearing. The hearing is a continuation of one that was aborted soon after it began last July 18 by a disturbance. Mr. Koch attended that brief session along with Police Commissioner Robert J. McGuire and was prepared to testify.

A senior Soviet official said today that it was ''wishful thinking'' for the West to hope that outrage over the shooting down of a South Korean airliner would prompt the Kremlin to make concessions in medium-range missile talks in Geneva. The official, Georgi M. Korniyenko, who is a First Deputy Foreign Minister, spoke at a news conference at which he and Marshal Sergei F. Akhromeyev, a first deputy chief of the General Staff, appeared to rule out compromises that might forestall or reduce planned missile deployment in Western Europe. Mr. Korniyenko also said demands for compensation for families of the airliner victims were ''irrelevant'' because financial and political responsibility for the destruction of the plane and the deaths of its 269 passengers and crew members rested with the United States, which he said had sent the civilian airliner on a spying mission. The news conference appeared intended to affirm the Soviet position in the face of the international outcry.

The nation's Big Three automobile manufacturers reported today that sales for the first 10 days of September were up 20 percent from very weak sales in the same period a year ago. Analysts expressed optimism for the the fourth quarter and for 1984. The three companies, the General Motors Corporation, the Ford Motor Company and the Chrysler Corporation sold 125,051 new cars, compared with 104,227 in the comparable period last year. There were eight selling days in the Sept. 1-10 period in 1983 and 1982.

Three radicals who said they were fighting for black liberation were convicted here today of murdering two policemen and a Brink's guard and stealing $1.6 million from an armored car in Rockland County nearly two years ago. The defendants - Kuwasi Balagoon, 36 years old; David J. Gilbert, 39, and Judith A. Clark, 33 - were each found guilty of all charges against them, three counts of second-degree murder and four of first-degree armed robbery. A jury of seven men and five women reached its verdict quickly. The jurors began deliberating at 11:37 A.M. and returned at 3:27 P.M. to render their unanimous verdict. During the deliberations they returned to the courtroom for 50 minutes, for a rereading of witesses' accounts of crime, which occurred Oct. 20, 1981.

Media General presents itself as a straight-arrow place where all employees and executives must subscribe yearly to the publishing, broadcasting and newsprint company's written code of business ethics. Thus, the allegations of income tax fraud, mail fraud and kickbacks at its subsidiary, the William B. Tanner Company of Memphis, have proved to be an embarrassing episode for Media General. ''Needless to say it was all very surprising to us,'' said Alan S. Donnahoe, Media General's longtime chief executive officer. Tanner Acquired Last Year The hometown newspaper company here has grown over the years into Media General, which has its roots in pre-Civil War newspapering. A conservative empire stretching far beyond its headquarters here, it had never encountered the image problems that the Tanner episode presented. The Tanner Company, which buys and sells broadcast time on a barter basis, was purchased last year by Media General for $39 million. Last month, 30 Federal agents descended on Tanner headquarters in Memphis seeking documents in connection with the allegations.