Here is a semi-reliable test for determining, on any given Tuesday, just how aggressively any federal regulatory agency is regulating the activity or industry it is supposed to regulate: noisy yelps and loud grumbles from the regulated group generally indicate that the agency is active. Not necessarily judicious, mind you, but active.

During our recent past, the brotherhood of strip-miners could usually be heard griping about the Environmental protection Agency. And of course, the Securities and Exchange Commission has never been a big favorite of those dealing in unregistered stock.

By the standards of this semi-reliable test, the Federal Election Commission, which oversees all congressional and presidential campaigns and their costs, must be a veritable dynamo of activity. You have rarely heard such grumbling and such resentment from any regulated group as that directed toward the FEC. The FEC is not like the other regulatory agencies mentioned. Robert Vesco, for example, does not have a vote on the FEC's budget or its authority. But the election commission's "regulated group" includes every elected member of Congress and the president, all of whom have something to say about the FEC's own expenditures and its very existence.

Many of the politicians' gripes about the FEC have been legitimate. The commission has been, during its six-year existence, guilty of chronic nit-picking. Three years after Jimmy Carter was inaugurated, the FEC was still cross-examining one of his primary challengers, Rep. Morris Udall, about $25 in petty cash from the New Hampshire primary. Anyone who has been close enough to a campaign to see a bumper sticker applied to a bumper knows that that $25 almost surely went for hot pizza and cold beer. Sometimes it seemed that if the FEC had been a traffic cop, the commission would have ticketed Santa Claus for double parking on Christmas Eve outside an orphanage.

The FEC, for most candidates for federal office, has been an irritant. Of course. Congress wrote the law that established the commission and its record-keeping duties. Still, there never has been a candidate who enjoyed revealing to the world, let along his opponents, where all the dollars came from or where they went. Candidates would prefer to preserve a little mystery.

Now as reports are heard of a White House-Senate Republican effort to gut the FEC, it may be useful to remember that the Federal Election Commission, any more than the EPA, was not created for the comfort and the convenience of its "regulated group." The FEC was put there to enforce the election law and to protect the public interest.

One of the whispered Republican proposals would require that candidate records of contributions and expenses by filed only with the secretary of the Senate and the clerk of the House. Both of these individuals are employes of Congress, serving at the pleasure of the leadership. It may come as a bit of a shock to the proponents of this change, but their idea is not a new one.

For many years, before the Nixon presidency, candidates filed reports with the Senate secretary and the House clerk. That was when the Corrupt Practices Act of 1910 was on the books. Ah, there was a law. Would that the Clean Air Act had given us anywhere near the amount of clean air as the Corrupt Practices Act produced illegal campaign activities. Millions regularly went unreported and unrecorded. Campaigns were awash in cash. The Senate secretary and the House clerk viewed their duties very narrowly. They simply received, without questioning, the reports. The Justice Department in those days simply refused to act until a specific matter was refused to it.None was. As a rule, people in the steno pool don't generally tell the chairman of the board when to return from lunch.

By now, most of us have learned that, under existing Republican doctrine, private is almost always preferable to public. Sometimes, however, there is no corresponding private entity to perform the specific task. That may be the case in campaign record-keeping. If that is the case it would seem that, under existing Republican doctrine, the unaggressive and impotent public sector - congressional employees -- is preferred to the aggressive and independent public sector -- the FEC.

Thanks only to the FEC, we now know that general election candidates for the Senate have spent $180.1 million since 1976. We know where it came from and where it went. We also know, thinks to the diligence of the FEC, that during the last three election, $276 million has been spent in House general elections and that in 1980 over $100 million was spent by presidential candidates.

The FEC does need to be improved. Common Cause, in a thoughtful study of the commission, urged several changes including making the chairman a presidential appointment for a four-year term. Under the present weak arrangement, the chairmanship rotates annually.

In 1972, 124 individuals gave $17 million to one presidential candidate. In 1980, there were 694,077 contributions to presidential candidates. We now have, for less than the price of a local phone call per presidential voter, a commission that for the very first time has made full compliance with the election law a reality. The FEC deserves to live.