US uses world airwaves to counter Soviet rhetoric about KAL incident

America's competition for the good opinion of the world means bouncing information off space satellites and organizing a specific campaign strategy in crucial contests. The business of countering Soviet propaganda goes on even while US Navy ships hunt for the crucial ''black box'' that may tell the story of the South Korean passenger plane shot down by a Soviet fighter.

Pro-Soviet propaganda is being sent out from Russia round the clock, officials here say. In response, the US Information Agency (USIA) puts out a continuous stream of information intended to put America's case before the world.

''When Korean Airlines Flight 7 was shot down in the Sea of Japan, the agency moved immediately to make the US position known throughout the world,'' USIA director Charles Z. Wick said last week.

Aimed at the Soviet people over the heads of the government, President Reagan's weekly radio address was broadcast on Voice of America (VOA) Saturday. Plans for the speech were kept secret so that the Soviets would not try to jam the broadcast, which was aired at 8 p.m. Moscow time Saturday, when many city people are out at their country dachas.

A senior VOA official says jamming is much less effective in the country than the city. From what VOA can gather, the broadcast was jammed in the usual way: the Russian-language version of the broadcast was blocked, but not the one in English.

The contest for the opinion of the world goes on all the time, director Wick says. It took a more active form in the Flight 7 episode, but USIA, the Voice of America, and other communication vehicles are active all the time, day and night , winter and summer, to whomever can be reached.

After the KAL downing, VOA broadcasts to the Soviet Union were increased by 40 percent. Statements by Mr. Reagan and Secretary of State George P. Shultz were sent to 51 posts worldwide. An extra item a week was added to the agency's new television satellite broadcasts, which are distributed weekly to some 150 overseas networks.

Odd languages are used: Dari and Pashto for Afghanistan; Azerbaijani for the Soviet Union, Turkey, and Iran; and Amharic for Ethiopia.

Though proud of the agency's work, Wick said he wishes he had better equipment. ''The VOA is operating with outdated and badly deteriorating equipment,'' he said. VOA was able to increase its broadcast hours, but couldn't turn up the volume, so to speak: ''Unlike other international broadcasts, we had no 500-kilowatt superpower transmitters to turn on.''

Wick noted that USIA resources have declined 27 percent since 1967 (in real terms) and its personnel level has declined 34 percent. ''Compared with USIA's budget of $496 million in fiscal year 1982,'' he said, ''the Soviet Union in 1982 had a budget of $2.125 billion for (information and exchange-type activities.)''