The Reagan White House got an American-made $5,000 FM band tuner as a Christmas gift yesterday from a Baltimore firm that wants the president to use it to begin replacing a Japanese stereo system that the head of the firm says is now in the White House.

The present came from Frederick E. Barrett, president of United Sounds of America Inc., a small company situated in an enterprise zone in Baltimore, the Park Circle Industrial Park. Reagan visited the enterprise zone last April when Baltimore Mayor William Donald Schaefer showed it to him as an example of that city's efforts to revitalize businesses and create jobs.

Reagan's enterprise-zone proposal failed to gain passage in the Congress but the president has said he plans to introduce it for the next session.

Barrett said he wanted the president to share in the "first fruits" of his company because Reagan, a strong believer in enterprise zones, had inspired his firm by visiting the industrial park and because the White House had a Japanese component stero system.

"I read that they have a Japanese system, and I got mad," said Barrett. "I guess they figured that the best technology is Japanese. I want to show them that the best can be made by Americans, and it can be made in the middle of tough neighborhoods."

The tuner produced by Barrett's firm, the Sequerra, was given the State of Art Award by Japan's largest audio magazine, Stereo Sound, for the last three years, Barrett said.

Barrett, an executive director of the U.S. Product Safety Commission under the Nixon administration, did not present the tuner to Reagan but left it with the White House secretary for gifts, Mary R. Power. Barrett attached a letter for Reagan, describing the tuner as "the crowning achievement of our efforts. Please accept this gift as a symbol of the continued energy, perseverence, creativity and hope of the American people."