Frustrated by their lack of power, homosexual activists attending the Democratic National Convention today sought to raise their visibility by seeking enough signatures to nominate District of Columbia gay leader Melvin Boozer for vice president.

With 77 openly homosexual delegates, alternates and standing committee members at the convention, the gay caucus here is the largest ever to attend a national political gathering. But despite their numbers, the homosexual activists have so far failed to make the publicity splash they wanted.

Most of the gays supported Sen. Edword M. Kennedy, and his withdrawal as an candidate is seen as a furthr setback for the homosexual movement.

"So far, we're not having much of an impact," said D.C. lawyer Tom Bastow, head of the organized effort that brought the 77-member homsexual group to the convention. In 1976, only four acknowledged gays attended the Democratic convention.

But with the party platform plank -- which deplores discrimination based on a broad list of criteria, including "sexual orientation" -- already settled, the gays found themselves lacking a central, media-grabbing theme. Some think the language in the platform should have been rejected so that gay activitists could deliver a minority report during platform arguments and capture a few minutes of precious television air time.

"There are a lot of groups here competing for press attention," Bastow said. "You've got to figure some kind of strong angle to get it."

As a last-ditch effort, members of the gay caucus began an attempt today to collect the necessary signatures of 333 convention delegates to have the name of Boozer, head of the D.C Gay Activist Alliance, placed in nomination for vice president.

Nominating Boozer could guarantee 15 minutes at the podium Thursday night. Two persons would be able to make seconding speeches, and Boozer would get to say a few words in declining the nomination.

There was enthusiasm among gays here today for Boozer, but disappointment at Kennedy's withdrawal and the inevitability of a Carter nomination.

"Carter's whole effort at humiliating Ted Kennedy is going to cost him the election in the fall," said Jim Foster, a gay leader and San Francisco political consultant who had worked full-time on the Kennedy campaign since last November.

Paul Kuntzler, a Kennedy atlernate and longtime D.C. gay activist, said he would probably support independent candidate John B. Anderson rather than Carter in the fall. He predicted that many other gays might approve of Anderson's "middle-of-the-road" economic policies, along with his strong stand in favor of gay rights.

Homosexual activists here say they are unhappy with what they call lukewarm stands by Carter on issues such as discrimination against homosexuals in the military and immigration laws against homosexuals, which have been enforced during Carter's term.

Kennedy, they say, had the strongest stand on homosexual issues, promising to issue an executive order banning discrimination against homosexuals. At last count, 54 of the 77 gay caucus members supported Kennedy.

Those who went with Carter said they did so for pragmatic reasons. "I made the assumption that Carter was going to win, and I thought there should be some of us working in that camp," said gay Los Angeles lawyer Richard Kaplan, a Carter alternate.

The homosexuals say, however, that despite their low profile in New York this week, they are still happy to be here in large numbers.

"There's never been a national gathering of popularity elected gay people," Bastow said. "The caucus earlier this week was the first one. It was a tremendous emotional high for all of us."

The homosexuals say they are also happy at winning a provision in the Democratic Party charter prohibiting discrimination in any party functions.

"The one big message we can send back is that we are here, we exist, we exist at the Democratic convention," said Gwen Craig, a black lesbian from San Francisco who said she has run herself ragged this week trying to attend all the black caucuses, women's caucuses and gay caucuses.

She said the fact that there are 77 gays here "is certainly a matter of pride. It means there are more people who are willing to stand up and say they are gay, to go out and get themselves selected as delegates. At last, we've developed the kind of organization and political clout you need to do that."

Most of the homosexuals here are from urban areas that have large concentrations of politically aware homosexuals -- San Francisco, Los Angeles, New York and Washington.

But there are also gays like 27-year-old Bob Warburton from Wyoming. "I get mixed reactions," said Warburton, a Carter alternate who said he didn't go with Kennedy because he didn't believe Kennedy could win. "Wyoming is a western state, and most people think any way you want to live your life is all right."

Warburton said his mother is also attneding the convention, as a Carter delegate. "She's farther to the left than I am," he said.