The fall television schedules came out a couple of weeks ago, and I searched in vain for the program that I was hoping for: "Meet the Presidents."

There are lots of new series, specials and sports extravaganzas. But nothing in the announcements indicated that any of the three networks is planning to devote six, eight or 10 hours this autumn to introducing or exploring the men who will be competing to lead this country.

There will obviously be increasing numbers of news segments about the candidates. But those brief, chopped up bits of reporting and analysis--let me say as a sometimes participant--are no substitute for what we need.

The frustration for the candidates, and the flaw in our present system of presidential selection, is that very few of the voters who now choose the nominees ever really get a chance to see the aspirants whole--in the round-- before they have to pick a president from the group.

Democracy assumes a fairly substantial degree of knowledge on the part of the citizenry about those who are vying to be their leaders. In a parliamentary system, like Great Britain's or Canada's, voters come to know the alternative prime ministers over time in their roles as leaders of their parties in Parliament. There are no unknown or little-known candidates.

The United States--wisely for our system of government--rejected the notion that congressional leaders automatically make the best presidents. We broadened the field of potential contenders to include governors, mayors and an occasional general, businessman or educator.

Until the 1960s, we dealt with the problem of sorting through these relative unknowns to find a president by entrusting the job largely to professional politicians--elected officials and party leaders. They filled the delegate seats in convention halls, returning year after year almost as a matter of right. The makeup of the group was small enough and predictable enough that even an unknown candidate could become familiar with them and to them in short order, as Wendell Willkie did in 1940 or Adlai Stevenson in 1952.

But in the last two decades, we have gone a long way toward letting everyone in the country have an equal say in picking the presidential nominees, through presidential primaries in more than half the states and open caucuses in the others. As the new crypto-national primary system has evolved, the critical choices that drastically narrow the field have come earlier and earlier in the process.

In 1984, many observers believe, the "front-loading" of the primary and caucus schedule will reduce the field of Democratic aspirants to two--or maybe one--by the end of March. If President Reagan does not run, the GOP field of would-be successors will be squeezed down equally fast.

What do the voters in the 20 or so states that may choose delegates in the first three months of 1984 know about the men who would be president? Darn little. How are they going to find out? From news accounts of the campaign that may be broadcast or printed in the coming months, but mainly from the advertising the candidates themselves purchase and prepare.

Is that a satisfactory or sufficient basis for making the choice? Well, advertising can convey information on issues--Reagan's certainly did in 1980. And the news accounts, I would hope, would cover at least some of those issues while keeping people current on the status of the horse race.

But where do the voters get their sense of the candidates themselves early in the primary season? I'm not sure that they do. It is different in the fall, when massive coverage concentrates on the two nominees. The voters generally do get a good fix on them. Not so when there are six or eight competing for attention in the frantic week-by-week scramble that is the primary season.

These thoughts were stimulated by watching former Florida governor Reubin Askew, surely one of the less-familiar Democratic contenders, spend an hour with a group of reporters last week. Askew chastised us--and properly--for our preoccupation with the mechanics of the race, the polls and the money figures. He succeeded in shaming us into drawing him out on more substantive questions.

He did not make much news, as that is usually defined in journalism. But all of us, I think, left the room with a clearer sense of the fires that had tempered Askew's steel and the impression of a man with an unusually clear sense of himself, his country and the demands that history might place on him if he were to become president.

That is the kind of picture the voters ought to have in their minds, not just of Askew but of everyone else seeking the presidency. It takes time to draw that picture, but it can be done--probably better on television than in newspaper type. Bill Moyers showed that with some of his hour-long televised "conversations" with candidates in the past. We need something like them again--and we need them soon.