Ever since Washington's only Spanish-language radio station went off the air last April, Hispanic community leaders have been working feverishly to find some means of delivering news and entertainment to the area's estimated 150,000 Hispanics. They have challenged the license renewal of one station, investigated the possibility of buying another, created committees to lobby for more Latino community coverage and Spanish-language programming from still other radio and television stations. All, so far, with little success.

"The situation is getting worse all the time," Silverio Coy of the Washington Metropolitan Coalition said yesterday.

But Coy and several other local Latino leaders found themselves some new allies yesterday at the first national conference on Hispanic public service programming.

The situation in Washington, as the conference made clear, is a reflection of the national problem, and one that the presence of several congressmen and Federal Communications Commission and media representatives indicated is the subject of widespread concern.

Rep. Edward Roybal (D-Calif.) noted that there are between 12 million and 16 million -- and perhaps more -- Hispanics in the United States. As many as 20 percent do not speak English.

The lack of adequate informative programming directed toward what demographers say will soon be the nation's largest minority has tended to cut Hispanics off from opportunities enjoyed by other Americans, according to William Medina, an assistant secretary of the Department of Housing and Urban Development.

"People cannot take advantage of the billions of dollars of (HUD) programs," Medina said. "if they don't even know about them to begin with."

The conference was jointly sponsored by the University of Maryland and the Johnson and Johnson Co., which has done a considerable amount of commercial advertising in Spanish and is now in the process of producing 60 new Spanish-language public service spots dealing with health care.

Though no concrete action came out of the conference, many participants thought it scored a psychological victory. "It showed awareness," said Coy, "that Hispanics are consumers, that Hispanics are part of this nation and Hispanics count -- and that, at least, is a beginning."