The Senate yesterday began live gavel-to-gavel radio coverage of its floor proceedings, with advance rave reviews from its leaders but no discernible impact on its behavior.

"History will record this as a red-letter day in the history of broadcast and the history of the Senate," said Senate Minority Leader Robert C. Byrd (D-W. Va.).

But the Senate, which plans to move on to an experiment with live television coverage on May 1, appeared to be taking its radio debut in stride. Within less than an hour after it hit the airwaves, the sounds of the Senate had a familiar resonance: the calming silence of a quorum call.

Silence in the Court . . . Don't hold your breath, however, waiting for the Supreme Court, the most secret branch of government, to follow suit.

Chief Justice Warren E. Burger recently turned down a request for live radio coverage of arguments next month on the constitutionality of a key part of the Gramm-Rudman-Hollings budget-cutting law.

"It is not possible to arrange for any broadcasting of any Supreme Court proceeding," Burger said in a letter March 6 to Mutual Broadcasting System's court reporter Stephen Nevas.

Burger declined to elaborate except to say in a handwritten note: "When you get Cabinet meetings on the air, call me!" The court's arguments are open to the press and public, but seating is extremely limited and no cameras or tape recorders are permitted.

Burger, a steadfast opponent of televised coverage, has said there will be no cameras in the Supreme Court "while I sit there." One of his objections has been that the networks would distort the court's work by showing only fragments of the court's one-hour argument. There have also been objections to having the court's arguments used for commercial purposes.

Mutual, attempting to surmount those concerns, said it would simply tap into the court's sound system, carry the proceedings "live, uninterrupted, unedited and without commercials" and offer them free, via satellite, to all radio stations and satellites.

It was not known whether Burger asked the other members of the court what they thought of the idea.

Farm Talk . . . Richard E. Lyng met with reporters yesterday for the first time since he was sworn in as agriculture secretary. Someone wondered if he would consent to hit the campaign trail in the fall on behalf of fellow Republicans. Pointing out that candidates often do not want agriculture secretaries out speaking for them, he said, "At this point, I suspect I'm at the peak of my popularity."

He also declined to name any of the names under consideration for USDA's deputy secretary slot. The rumor mill of late has made grist of Peter C. Myers, a Republican farmer who was head of the soil conservation service until last year, when he became assistant secretary for natural resources and environment.

Another name circulating as a strong candidate for the job is that of George Dunlop, staff director of the Senate Agriculture Committee and longtime assistant to the chairman, Sen. Jesse Helms (R-N.C.).

Meal Appeal . . . The federal judiciary has a way to meet budget cuts required by Gramm-Rudman-Hollings: stop feeding jurors. A proposal to do away with free lunches, routinely offered in some areas, is now before the Judicial Conference of the United States, the judiciary's policy-making body composed of the heads of the 13 appeals courts and 12 district courts and Chief Justice Warren E. Burger. The proposal would allow free meals for sequestered juries and during deliberations, but not while jurors are waiting to be called or while they are hearing a case.

In jurisdictions where lunches are provided -- a minority of the judicial districts -- the meals range from catered lunches and dinners to cafeteria fare. Sources say the proposal could save hundreds of thousands of dollars for the judiciary, which is trying to cut about $42 million from its $1 billion budget to meet Gramm-Rudman for this year. The conference is expected to vote on cuts today.

No Comment . . . It was a slow Wednesday afternoon in the Senate Foreign Relations Committee meeting last week when the agenda came around to the nomination of Morton I. Abramowitz as the State Department's new assistant secretary for Intelligence and Research. It was Sen. Jesse Helms' (R-N.C.) turn to question Abramowitz, a career foreign service officer who has actually been running State's intelligence bureau as "director" for more than a year. His superiors recently decided to upgrade the position, and Abramowitz was expected to sail through the confirmation process.

"Do you, sir, think that the United States Government should take any steps which would have the effect of encouraging the Republic of China to negotiate its future with Communist China?" Helms asked.

The small audience in the hearing room was jolted to attention when Abramowitz refused to answer, explaining that as the department's chief intelligence officer he was not involved in policy.

Helms persisted, but got no answer. After the hearing, Helms complained in a letter to Chairman Richard G. Lugar (R-Ind.) that, because assistant secretaries of state traditionally have been policy-makers, Abramowitz should answer the question. Helms is now threatening to hold up Abramowitz' appointment, according to Senate sources, and has asked that Secretary of State George P. Shultz send someone up to the committee to explain whether the new intelligence czar of the department will have a policy role. Even Abramowitz further clouded the issue when he acknowledged that he did have a small policy role as a member of an interagency committee that supervises "sensitive intelligence activities."

Abramowitz could not be reached for comment, but sources said he is being "counseled" to make his peace with Helms