President Reagan will soon surpass President Jimmy Carter's record number of appointments to the 761-member federal judiciary. Carter picked 245 judges; Reagan has picked 207, and there are 90 vacancies.

Ten Reagan nominations are pending in the Senate and nearly 80 are in or about to enter the administration's selection process; another 40 seats are open.

Reagan is likely to pass Carter's mark by the end of this year, and, with normal attrition rates, he may accomplish what only presidents Franklin D. Roosevelt and Dwight D. Eisenhower have done in the last 50 years -- appoint a majority of the federal judiciary.

According to figures compiled by the Administrative Office of the U.S. Courts, Roosevelt appointed 81.4 percent of the bench; Harry S Truman, 46.5 percent; Eisenhower, 56.1 percent; John F. Kennedy, 32.8 percent; Lyndon B. Johnson, 37.9 percent; Richard M. Nixon, 45.7 percent; Gerald R. Ford, 13.1 percent, and Carter, 40.2 percent.

The administration has taken somewhat longer than expected to fill vacancies, but the process has speeded up as Attorney General Edwin Meese III completes selection of his key aides.

Meanwhile, Congress may take an action that could expand the potential candidate pool. A House Judiciary subcommittee is considering legislation to increase fringe benefits -- especially survivors' pension payments and travel allowances.

A group of judges testifying last week warned of a judiciary that would be dominated by the "wealthy and the mediocre" unless benefits are raised.

Judges are "not in any state of crisis or riot or rebellion," Appeals Court Judge Frank Coffin told the subcommittee, "but there is a deepening, bone-deep frustration." Coffin said he knew "quite a number" of young judges with families who have "reached the end of their rope."

U.S. District Court judges now earn $76,000 a year, but the surviving spouse of a judge who served five years receives pension payments of less than $400 a month.

"The program presently offered to the survivors of deceased federal judges is so bad and inequitable that it is embarrassing," said Judge Spencer Williams, president of the Federal Judges Association.

Often required to travel to hear cases and attend meetings, judges receive $75 a day for food and lodging. That is inadequate, Williams said, and frequently compels judges to pay much of their travel costs. It is "blatantly unfair and possibly unconstitutional to require judges to bear their own expenses under these circumstances," he said.

Chief Judge Charles Clark of the 5th Circuit said fringe benefits are especially important considering that judges are paid less than half the amount earned by most top lawyers in private practice.

"We are soon going to have a cadre of federal judges composed of the independently wealthy and the mediocre," Clark said, "because you are not going to be able to attract a lawyer who is at the top of the profession . . . if he's making $200,000 in private practice" by offering less than half as much and requiring that he pay some of his own expenses.

Various proposals in Congress would guarantee surviving spouses at least 30 percent of a judge's annual salary. One bill would allow for full reimbursement of travel expenses, under a "reasonable" ceiling set by the U.S. Judicial Conference.

With the 200th anniversary of the U.S. Constitution barely two years away, the 23-member Commission on the Bicentennial is still looking for a staff director and worrying that it may not have enough time or money to put together an appropriate celebration.

The search committee, chaired by Washington attorney Betty Southard Murphy, has gone through resumes from dozens of applicants for the $86,200-a-year job.

The commission, chaired by Chief Justice Warren E. Burger, met for the first time last week at the Supreme Court and voted unanimously to ask Congress to allow it to produce coins, medals and stamps and to allow it to use a logo -- still to be designed -- to raise revenue.

Worried that the proposed $775,000 budget for next fiscal year will not be adequate, the commission wants Congress to raise the ceilings on individual contributions. By law, individuals may contribute no more than $25,000 in any one year to the bicentennial. Corporations are limited to $100,000 annually.

The meeting, apparently like those of the Founding Fathers, was closed to the public. Subsequent meetings, such as one planned Aug. 22 at the Hotel Utah in Salt Lake City, also will be closed, according to Supreme Court press officer Toni House.

The commission also voted to support the creation of a one-time national holiday on Constitution Day, Sept. 17, 1987. That also happens to be Burger's 80th birthday.