Restless conservatives impatient for President Reagan to signal that he will be a candidate for reelection are taking matters into their own hands with a series of informal meetings designed to promote his candidacy.

The meetings, confirmed by several key Reagan political operatives from past campaigns, are intended to fill a political vacuum that has become increasingly worrisome to some of the president's original supporters.

"There was concern from the beginning whether Reagan would be a one-term president or not," said one of his former field directors. "There hasn't been enough concern for keeping the 1980 coalition intact."

Already, longtime Reaganites have met to discuss reelection strategy in Missouri, Texas, Utah and Wisconsin, and similar sessions are planned soon in Illinois, Indiana and Ohio.

Reaganites from a dozen western states will meet in Denver the last weekend of this month to discuss the prospects for 1984.

Lyn Nofziger, the former White House political adviser who now is the sparkplug of the effort to prod Reagan into an early announcement, has arranged and attended many of these meetings. An earlier public attempt by Nofziger to launch a reelection effort was repudiated by the White House but the current arrangements have at least informal sanction from people close to the president.

Nofziger stressed, however, that the meetings are informal and involve no expenditure of funds.

For this reason, he said, they do not require a formal filing of candidacy or formation of an official committee under federal election law.

Sen. Paul Laxalt of Nevada, whose appointment as general chairman of the Republican Party has been taken by many Reaganites as a sign that the president will seek a second term, is aware of some of these meetings. He said they are merely forums for discussion at this point.

"I believe First Amendment rights apply to politicians," he added.

But the White House is concerned that zealous backers of the president may inadvertently take actions that would make Reagan speed up his own timetable.

Reagan has said he has made no decision on whether to run again, but many of his top aides predict that he will be a candidate.

"We don't want to be put in a position of either disavowing people who support the president or admitting a candidacy before the president is ready to do that," said White House chief of staff James A. Baker III, who says he believes the president will decide to seek a second term.

Laxalt, who said that he does not think any announcement is likely before late this summer, discounts the need for Reagan to send any additional signals at this time.

"I don't find anyone in the Reagan family who doubts he's going to run," said Laxalt, who is close to the president.

But some equally loyal to Reagan do not share this view.

They point out that Reagan is 72 and that legitimate doubts persist about whether he wants to spend six more years in the White House. They express concern that the White House staff does not understand the effort required to put a campaign organization together, even by a sitting president.

Some also say they worry that delay will encourage other Republicans who will start out as contingency candidates and then become serious about their effort.

"We don't need a formal announcement but we need a strong indication," said Nofziger. "First of all it will be easier for Reagan to get from the Republicans in Congress what he wants if they know they'll have to deal with him for six more years. Secondly, the longer he delays the more difficult it will be to get the organization back again because people will drift away into Senate and other races.

"Thirdly, as a matter of fairness, if he doesn't run, he's got to tell the other prospective candidates what he's going to do because it will take them time to raise money and put a campaign together. The election is closer than many people think. We're nine months away from the filing time in Illinois."

Key Reagan operatives across the country have differing views, with some saying they are quite prepared to wait until Reagan is ready to announce. But a number echoed Nofziger's concern.

One of these said the feeling is "that this White House is not our White House" and that there is no sign that oldtime Reaganites will be included in the campaign.

"Laxalt for now is just handholding us, saying the budget fight has to be taken care of first," said this Reaganite. "But the feeling is widespread; it's injured pride on our part and as a matter of principle, we think it ought to be our campaign."

Others discount the political experience of the top trio of White House aides--Baker, White House counselor Edwin Meese III and deputy chief of staff Michael K. Deaver.

Of them, Baker has the most political experience but he is suspect among some conservatives for his management of the presidential campaigns of Gerald Ford and George Bush against Reagan. Others who like Baker say he "started at the top" as a manager and strategist and does not value grass-roots organization.

"You don't have a political White House," said one key Reagan operative from the 1980 campaign. "The institutional memory, outside of political adviser Ed Rollins and deputy political adviser Lee Atwater is not there. Meese is not a politico. Mike doesn't fit that role and Jim wasn't for Reagan until he was forced to be. So you don't have people over there who are sensitive to this."

Nonetheless, there is a widespread belief that Baker will have a key role in any Reagan campaign. Others observe that it was Baker, mindful of the conservative concern, who reached out and asked Laxalt to be the general chairman of the GOP with the understanding that he would ultimately play a similar role with a Reagan reelection committee.

The concept is that Laxalt would be the overall Reagan chairman, as he was in 1976 and 1980, while a nuts-and-bolts politician would be brought in to run the reelection committee and closely coordinate with the White House. Many believe that Stuart Spencer, Reagan's chief strategist in 1980, would again be called in to play this role.

In the lofty regions of the White House, which one Reagan operative described as "an ivory tower," the stirrings on the hustings tend to be treated as a minor matter. The big-picture view is that Reagan is still popular and will stage a comeback if the economic recovery gathers momentum and he is perceived as genuinely striving for arms control.

The White House view is that Reagan will decide when he is good and ready and that the troops will be there when he does. But it looks different on the outside to many of those who have toiled in the vineyards for Reagan.

"I don't think we can win without the organizational effort we had last time," said one of Reagan's 1980 field directors. "The economy makes it possible for you to win if it comes back. It doesn't make you a winner."

The administration may try to address these concerns beginning today at a three-day meeting of supporters who will attend the annual Conservative Political Action Conference at the Sheraton-Washington Hotel. Reagan will address the conference, as will several Cabinet officers.