Fred Silverman was flamboyant, impulsive, outspoken and, associates say, sometimes hysterical. His successor as the top boss at NBC, Grant A. Tinker, appeared to be none of those things when he spoke at a press conference last night at New York's fashionably stuffy 21 club.

Tinker, 55, formerly the head of MTM Enterprises in Hollywood, took note of the relatively large turnout for the informal affair and said he attributed that to the "notoriety and celebrity" of his predecessor. On July 1, Silverman resigned, and on July 8, Tinker officially became chairman and chief executive officer of the financially ailing, low-rated network.

Except for the reference to his "notoriety," Tinker had only kind words about Silverman, calling him "a brilliant guy" and saying of his failure to loosen NBC's firm grip on third place, "Fred Silverman had a lot of bad luck -- I mean a lot of bad luck -- and I would hope not to have as much."

Outwardly businesslike, exacting methodical and clearly determined, Tinker looks less like a broadcasting executive than maybe an oil millionaire or a square-jawed celebrity lawyer. He said of himself, as he has said before, "I love to mingle with creative people, but I don't consider myself one."

Of his plans for revolution at NBC, the man whom some NBC employes are already referring to as "Uncle Grant" (although Mister Grant would probably be a cuter nickname) said, "I would like to see us do less of the really rotten shows." He did not name any specific titles, but on the NBC schedule there are many to choose from.

Yet at the same time he seemed to be issuing a new mandate for parsimony in the production of network television shows. "The golden goose, if not dead, is not thriving," Tinker proclaimed. Perhaps appropriately, the last MTM business Tinker recalls conducting with NBC was an unsuccessful attempt to sell a comedy show to the network called "Nickels and Dimes."

Nickel and diming time appears to have arrived at NBC concurrently with Tinker's appointment.

Many reporters pressed Tinker to speak out against the Moral Majority, the Coalition for Better Television and their campaigns to scrub the airwaves clean the smut and guts.Tinker refused to be forced into heavy rhetoric; he said the networks were giving the Rev. Jerry Falwell and his followers ammunition by putting on "too many not-very-good shows," and said, "If television was better, they would go bother somebody else. I got a nice letter from Rev. Falwell, by the way. He's expecting great things of me," Tinker said with a sly smile.

"As far as I'm concerned, he is another viewer, and I would be interested in what any viewer says. Obviously he is more vocal than most."

Tinker did not propose anything revolutionary insofar as tinkering with the system of network televisoin as it now exists. He did seem to be promising less pressure on producers to throw shows together so rapidly that there was little if any chance that they would amount even to half a hill of beans.

"In the white-hot competition of television," Tinker said, "there has been a tendency to move too quickly in that regard." Reporters were forbidden in advance by an NBC spokesman from asking anything about the terms of Tinker's agreement with RCA, NBC's parent company. In response to a question about who will fill the now-vacant president's post at NBC, Tinker said only that whoever he appoints will not be a woman. "The people I have in mind do not include a woman," he said.

Shows produced by MTM will not get special consideration at NBC Tinker said. "If MTM makes a good show, and I think some of them have been okay, I'd like to see some of them on NBC," Tinker, the ex-husband of Mary Tyler Moore, said. "But that door is very firmly slammed behind me."

The only MTM show now on NBC is the critically hailed, but poorly rated, "Hill Street Blues." Tinker said he thought one reason the show has failed to catch on was the way it was scheduled and that because it was "a very complex and complicated show on purpose," it would no longer be aired in "two-hour hunks" because that is "too much to ask of the audience."

Many of the reporters on hand were from the trade press that covers television from New York, and several of them surged forward at the end of the press conference to entreat him with more questions and comments. One reporter actually called out, "Well said," after Tinker's remarks. The atmosphere in the room seems to suggest that Tinker was a hero who had come to save the village of NBC from what the evil dragon Silverman -- the Vermithrax Pejorative of television -- had done. Such whimsical interpretations of reality are probably common at moments such as this, and many in the room appeared anxious to ally themselves with this rather mild-mannered new order.

Similarly, insiders at NBC say the atmosphere and morale at the network are spirited, optimistic, positively giddy with great expectation. Why, there hasn't been anything like this at NBC since -- since -- Fred Silverman took over three years ago.