When Joseph P. Yeldell went before the news cameras 11 days ago to announce his voluntary and temporary departure as Mayor Walter E. Washington's general assistant, there were traces of the defiance, pugnacity and sense of racial persecution shown in a similar situation 18 months earlier.

This time Yeldell was calm and subdued. He announced no plans for a defense rally on his behalf. He said nothing about letting "the chips fall where they may." Before he had declared, "Joe Yeldell ain't going nowhere ." This time, Joe Yeldell asked to be sent somewhere - home on leave, so he could prepare his legal defense against him earlier that day.

Yeldell stood alone in the doorway of his office the night of the indictiment, reading abrief 115-word statement that avowed his innocence and labeled the charges "groundless". When finished, he turned and quietly walked away. He has not been heard from publicly since then, except for saying "no comment" to reporters' questions and pleading not guilty at his arrangement last Thursday.

There seems to be a very different Joseph Yeldell.

The change in public posture, according to some persons close to both the mayor and Yeldell, stems from a very different set of circumstances beneath the surface of the current affair.

No longer, these persons said, does Yeldell have any kind of festering wide-spread public rage that he could use as leverage to exert pressure on the mayor or his accusers. No longer, they said, can rallies, threats and press conferences make significant changes in the sequence of events.

One mayoral confidant suggested that despite the mayor's entrenched loyalty to his close friend and associates - and Yeldell has been one of the closest - the mayor himself may have soured somewhat towards his longtime ally and political benefactor.

After all, an acquaintance of both men suggested recently, the stakes are different now than 18 months ago, when Yeldell was fighting mainly against accusations brought by the news media that he had improperly used his position to put friends and relatives on the city payroll.

"This time it really is different," the acquaintance said last week. "Here you have a sharp and simple development - you have an indictment. It's a formal charge by an official agency. It's not a whole lot of garbage that the papers are printing, much of which is wrong, anyway."

"I think he's realized it's serious and he can't win his case in the newspapers," said another friend. "It's not Joe Yeldell agiainst the newspapers. It's not Joe Yeldell against the mayor. It's Joseph P. Yeldell vs, the United States of America."

Yeldell, the former director of the D.C. Department of Human Resources, was indicted April 6 along with multi-millionaire developer and parking lot magnate Dominic F. Antonelli Jr. on charges that the two men illegally conspired in the awarding of a profitable $5.6 million city lease to Antonelli.

The indictment alleges that Yeldell pushed for awarding the 20-year city lease on a building at 60 Florida Ave. NE which Antonelli on several occasion guaranteed a bank loans Yeldell held at an Antonelli bank, the indictment says, and also gave Yeldell a $33,000 third trust on his home, lending the money at a favorable interest rate and concealing its origins through a "straw man" arrangement.

Immediately after the indictment was handed up by a U.S. grand jury, the mayor placed Yeldell on temporary leave of his duties. Shortly after that, Yeldell requested longer annual leave and temporarily has been replaced as the mayor's general assistant by Lacy Streeter. The Antonelli Yeldell trial has been scheduled for Sept. 18.

Mayoral insiders who are willing to discuss the behind-the-scenes factors of the current situation contend that Yeldell's bold actions in November and December 1976 were possible in large part because the jury of peers was the public and Yeldell was simply more masterful at pleading his case.

It began on Nov.18, when The Washington Star published stories alleging nepotism and cronyism on Yeldell's part in DHR hiring. Then, the Star and The Washington Post began publishing competitive daily stories about the Yeldell, department and in the developing political drama, the mayor launched an investigation.

Yeldell ten defied a mayoral directive and staged a rally of 2,000 city employees, friends and supporters to declared his innocence, and branded the news reports as an attack on black leadership by a white-owned media.

Angered by Yeldell's actions, the mayor temporarily removed Yeldell as DHR director. When Yeldell threatened to provoke more controversy by returning to work against the mayor's wishes, the mayor removed Yeldell for four months. Yeldell left defiantly, proclaiming, "This may involve many people in the District government. I am prepared to let the chips fall where they may."

That drama, which soon became known as the Yeldell affair, evolved as the toughest political crisis for the mayor since the election in 1974, and many of his own friends said privately that his handling of it cost him political points.

Several mayoral insiders now agree that despite the variety of charges at the time - the first story raising questions about the leasing arrangement for which Yeldell and Antonelli were indictd appeared Nov. 19 in The Post - nepotism and cronyism were the key accusations in the public mind.

Yeldell, these sources said, was able to successfully protray these charges as racist in origin and thereby make the mayor, who like Yeldell is black, reluctant to take harsh action against Yeldell.

"he mayor could see that a good number of people in the black community would have seen it decided on a black-white basis and a good number of people in the White community were scared to death of seeing it resolved in that manner," said one mayoral confidant who was involved in that decision.

So Washington transferred Yeldell temporarily to the chairmanship of the obscure Board of Appeals and Review, allowing Yeldell to continue drawing full salary. After seven city reports found no evidence of wrong doing by Yeldell, the mayor mortgaged a bit of his own political future on Yeldell by first returning him momentarily to DHR and then making him the No. 3 man in the administration.

On the very next day, however Yeldell acknowledge in an interview with The Post that he had on two occasions sought Antonelli's help in securing loans to bail himself out of personal financial problems. According to a mayoral spokesman at the time, Yeldell had never told that to the mayor. That, according to one key mayoral confidant, changed the issue and possibly the mayor's feelings somewhat.

"I find it hard to conclude that he wasn't taking advantage of his position and that he should then surprise the mayor by not telling him directly but through The Washington Post," the confidant said.

"Here you wake up one morning and you see Yeldell is almost boasting to the newspaper, "Look how confident I am that what I did was all right." I think that conditioned a lot of thinking in the community.

"Joe made a horrible mistake . . . After this, he goes out and gets indicted and its pretty damn difficult . . . to say that the indictment is based primarily on race."

In the most recent incident, there were some differences between Yeldell and the mayor over what to do after the indictment. For a few hours, there was no agreement. One stumbling block, according to several persons in mayor's office at the time, was whether or not the mayor would use harsh language when he announced that he had placed Yeldell on administrative leave.

Corporation Counsel John R. Risher Jr., who in the past has opposed Yeldell within the mayor's close circle of advisers, had drafted a statement saying that the mayor was putting Yeldell on leave because it was the strongest action that could be taken, according to several sources.

"Joe didn't like it," one source said, "because that suggested the mayor would have fired him if he could." That segment eventuallt was removed from the statement.

It is still not clear why Yeldell and the mayor were at odds on how the administrative leave order came about.

Yeldell initiated the subsequent request for annual leave. Those close to him said it was because he know that preparing his legal defense would take more than the miximum of five days allowed by admimistrative leave procedures. Others contradict that. "The fact that the option for suspension was lclearly there," said one mayoral confidant.

It was still unclear at the end of last week just how much paid annual leave time Yeldell has. Mayoral spokesman Sam Eastman said that so far Yeldell has requested only 240 hours undor of the 618 hours he is said to have. Eastman said he is confident Yeldell is entitled to more than 240 hours under the somewhat detailed civil service formulas, but it is not clear now just how much more, he said.

The continuing public reaction to the indicentment of Antonelli and Yeldell has been decidedly cautious and varied. Most people feel that the indiciment is bound to have some political effects on the mayor, who is expected to announce plans to run for reelection within the next two weeks.

Ralph (Petey) Green spent condiderable time on last week's version of his WOL radio call-in show, "Rap with Petey Greene," talking about Antonelli, as portrayed in the first of a three-part series of articles in The Post. Greene said Antonelli's route from rags to riches presented an example for poor children to follow. He especially noted that Antonelli had at one time been unwelcome in the MayFlower Hotel because his clothes were too dirty. Later, Antonelli and some friends had so much money they could purchase a hotel.

Greene said it was tragic that Yeldell had been indicted for a transaction from which the formerDHR director got nothing more than a loan, according to the indictment. He felt the indictment could not be linked to the fact that Yeldell is black.

One caller agreed, saying that Yeldell and other city officials had betrayed poor persons in the city. Another caller, as well as Greene's cohost Herbert Barksdale said that Yeldell's indictment was part of a vendetta against black leadership in the city.

That view was echoed in last week's edition of "From the Desk of Lil," a column in the Washington Afro-American written by Lillian Wiggins.

"One can easily ask what's behind the 'get Yeldell move? It is clear there is one," wrote Wriggins, who has been a strong Yeldell supporter. "If we allow this kind of tactic to be practiced in our community, it is Yeldell today but who will be tomorrow? Better still, will there be a tomorrow for blacks in D.C.?"

Nearly two-dozen people called in on Rolnald Jaye's "Opinion Line," show broadcast Saturday morning over WUST radio. The basic question was whether the indictment would affect the mayor's chances for reelection, and general feelings about the indictment itself.

"I think it's going to have this much of an effect," one caller said. "It's going to have enough effect to keep me from voting for the mayor."

"I will vote for the mayor, still," said another caller. "They (Yeldell, Washington and other black leaders) make mistakes just like other people. They're both good men. I'm 100 percent for them."

Some callers linked the indictment to other things they swa as a master plan to force blacks out of local government and out of the city, generally. They blamed the news media for putting too much emphasis and details into its stories.

The detailed examination of the two men's lives - in a lengthy three-part brought mixed responses of antother sort:

Some of the callers felt that Yeldell had been used by Antonelli. Others felt he should not have gone to Antonelli in search of help with his personal financial problems. "It's dangerous to have a man tied up eith people like that," one caller said. "If Yeldell couldn't afford his house, he should have found another job."