Bernard Kalb, who harassed State Department spokesmen for nine years as a diplomatic correspondent for CBS and NBC news, made his Washington debut yesterday on the other side of the podium. "So this is what it looks like from up here," he said.

In his debut as the State Department's new assistant secretary for public affairs, Kalb lived up to his reputation for flamboyant dress and jocularity. He maintained recent tradition, too, opening the noon State Department briefing 25 minutes late. "This is a very, very large step for me," he said. "I trust that it will not jeopardize the future of the world."

Sporting an orange tie and handkerchief, Kalb announced that anyone similarly attired would be allowed to ask the first question. Asked for his home phone number, he paused. "Let me say that it is not true that I have spent the last few weeks seeking to retrieve ambiguity from the low esteem into which it has fallen," he said.

Kalb, 62, actually opened his new act last week in Geneva where he was in charge of saying absolutely nothing to 700 reporters frustrated by 48 futile hours of trying to find out what was going on in the talks between Secretary of State George P. Shultz and Soviet Foreign Minister Andrei Gromyko.

"I had high visibility, easy access -- and silence," he said. "I discovered that the job of spokesman is regarded as the world's seventh oldest profession. The other six obviously are classified."

Kalb knows what frustrates reporters. He was a New York Times reporter from 1946 to 1961, joining CBS in 1962 and serving in Southeast Asia, Paris and Washington. He joined his younger brother Marvin on CBS' diplomatic beat in 1975 and together they moved to NBC in 1980. Kalb accepted his new job in November.

He was in top form yesterday getting off the department's classic one-liners in response to thorny questions: "I'll have to stick to the guidance on that . . . I haven't anything for you . . . I can't be drawn into discussions on confidential exchanges . . . it's not for me to speculate."

Kalb paid tribute to his predecessor, John Hughes, who is returning to Massachusetts to run a small chain of newspapers, and to departing deputy spokesman Alan Romberg for teaching him these lines. He said he hoped Romberg's future, which is not yet decided, "treats him with the generosity that I believe all spokesmen deserve."

Kalb got a round of affectionate applause from his former colleagues before his appearance, and another one afterward. Marvin Kalb was pleased. "I called him and said, 'Our mother and father would have been very proud to see you today,' " he said. Their parents died several years ago.

Asked what he had thought of his own performance, Bernard Kalb's reply was vintage we'll-get-back-to-you Foggy Bottom: "I'll take that question," he said.