Los Angeles — If anyone from Soviet-bloc countries should decide to defect to the West during the Olympics this summer, that person will need to know how to go about it.
Thus a coalition of conservatives and ethnic groups ranging from the American Conservative Union to the Baltic American Freedom League has made elaborate plans for helping defectors make their break in Los Angeles.
The group laying these plans, Ban the Soviets Coalition, has been lifted from obscurity in recent days by the scathing, full-throated vituperation of the Soviet press, which has accused the group of scheming to kidnap top Soviet athletes and coaches.
As a result, this Orange County-based group of anticommunists and religious and ethnic groups has been sprung to the status of major player in an Olympic publicity war.
At a meeting in Lausanne, Switzerland, last week, Soviet Olympic officials asked for American assurances that this coalition would not be permitted to disrupt the games with demonstrations.
Ban the Soviets Coalition plans to post between 25 and 50 billboards around the city, written in Russian and German, touting a toll-free telephone number for defectors to call. It plans to hire an airplane to tow a message with the number across the sky over places where Olympic crowds are congregated.
Members plan to man the phones 24 hours a day with volunteers who speak Russian and other eastern European languages. They claim to have contacts working within the Los Angeles Olympic Organizing Committee (LAOOC) who will be in contact with Eastern-bloc athletes and spectators, ready to help guide defectors to the right people.
They are lining up hundreds of ''safe houses'' around Los Angeles where defectors can be spirited away until a press conference can be organized.
For the Soviets, Ban the Soviets Coalition has become a focus in criticizing security preparations at the Los Angeles Olympics. Security, reportedly, is still an issue of contention between Soviet Olympic officials and American organizers.
Last week the Soviet weekly Literary Gazette suggested that the coalition's director, who is an author and vice-president of a small Orange County advertising firm, be removed from the scene during the course of the Games.
LAOOC president Peter Ueberroth has responded with disdain for the coalition, calling it a ''nutty group'' and a ''minor embarrassment'' that has taken advantage of the games by using them as a soapbox for its own political agenda.
According to Ban the Soviets Coalition leaders, the attention in the Soviet press serves their cause by helping to alert potential defectors that there is a support system for them in Los Angeles.
Coalition director David W. Balsiger explains that most defectors will first ask for asylum from someone in uniform, such as a police officer. But if a defector reaches the coalition first, either through contacts or the telephone number, then members will whisk him away from the ''government net'' until a press conference can be set up.
Once an asylum-seeker goes public, Mr. Balsiger says, very few are returned to home-country authorities. He wants to avoid situations like that of the Soviet diver who requested asylum in the 1976 games in Montreal, only to be persuaded in a private session with Soviet officials to return to the USSR.
Balsiger says coalition members have infiltrated the LAOOC at the lower levels where they will be in contact with Eastern-bloc athletes, spectators, and , to a lesser degree, journalists and security officers. Some sympathetic LAOOC staff members and volunteers have called the coalition, as well, according to Balsiger.
The Ban the Soviets Coalition also plans to stage demonstrations at Olympic sites. Its message is that the Soviets are violators of human rights who use the Olympics for their own political purposes, chiefly, to legitimize their system through athletic success.
Various groups in the coalition are driven by different specific grievances, from Baltic nationalists protesting the Soviet annexation of their ethnic homelands to Roman Catholics angered at Soviet repression of their church. But the coalescing incident was the Soviet downing last September of Korean Air Lines Flight 7.
The coalition first tried to keep the Soviets from joining the games, circulating petitions and lobbying against allowing the Soviets harborage for the ship and 25 Aeroflot planes that will accompany the team this summer. Since losing this lobbying battle, the group has geared itself toward fighting an Olympic publicity war against the Soviets.
The coalition is also concerned about Soviet intrigue during the games. Another coalition figure is Tomas Schuman, a Novosti press agency editor and Soviet Embassy officer in India before defecting in 1970.
Mr. Schuman now writes for a Russian-language newspaper in Los Angeles. In 1967, he toured the vessel the Soviets were sending to Expo '67 in Montreal, a sister ship to the one headed for Los Angeles this summer.
The lower deck, he says, was full of radio sets, scanners, and recorders -- not to listen to secret conversations but to assess local communication capability. The Soviet ship in Los Angeles will be put to the same purpose, he surmises. Further, it will be a ''floating prison'' to keep potential defectors safely aboard, he says.