With a sherry toast and an audience of viewers who have been waiting six rocky years, the Howard University television station, WHMM-Channel 32, debuted last night.

"I'm so thrilled, I probably can't be analytical," said a beaming James Cheek, the school's president. "There were skeptics who never thought we would do it. But I'm really proud."

Cheek was part of an invitational audience of about 800 at the university's Blackburn Center that munched on meatballs and cheese while watching the first hour of introductory and congratulatory programming. "This is a very fine opportunity because the commercial stations and even some of the public stations have not lived up to their responsibility. They only look at the black, no pun intended," said broadcaster Edward P. Morgan, a member of the university's board of trustees.

Immediately Mayor Marion Barry, who had proclaimed the day in the new station's honor, saw an opportunity for an expanded expression of his views.

"Television is more powerful than the written news," said Barry. He was asked if that would mean better access for his side of the story. "We've been very successful with the university's radio station, WHUR, and there's no reason to feel otherwise."

The station, which is owned and operated by Howard, has a staff of 30 people. The programming, from 6 to 11 p.m. five nights a week, ranges from university-produced broadcasts to the programming of other PBS stations. As for public affairs, the station plans a daily "Evening Exchange" which will be in magazine format, and a once-a-week consumer program. Eventually the station, which has cost $7 million so far, will have to solicit funds from its viewers. The first day, says Avon Killion, the program's director, was hectic: "We were making changes until 7:30 on the logs . . . we had to hustle."

Evans Crawford, the dean of Howard's chapel, said he had already taped three "evening meditations," for the new station, to run three minutes each. As for the value of television as a religious tool, he commented that TV was being used best when it sparked dialogue.

Though the sound was scratchy at the reception, the guests, who included officials and public broadcasting types, thought the debut marked a milestone in broadcasting. "WHMM is an excellent position to improve not only black images in television but more importantly to serve as a training ground in telecommunications," said Dwight Ellis of the National Association of Broadcasters. Told that a lot of people had high hopes for his station, Cheek replied, "I don't object at all to high expectations. My philosophy is that your reach should extend beyond your grasp."