You might expect Ralph Nader to denounce "the Nielsen rating tyranny" that rules network television, but you probably wouldn't expect a television network to give him a platform for the denouncing. NBC has done that, however, as part of a new series of image-enhancing spots keyed to the theme "NBC, Tuned In to America," and unveiled yesterday at the jubilant NBC affiliates convention in Maui, Hawaii.

Nader, the consumer advocate, is one of nine citizen viewers who'll be seen in the 30-second announcements, which begin airing June 25 and will eventually be seen in all of what networks call "dayparts," sign-on to sign-off. Each spot consists of one or two people holding forth, spontaneously and in their own words, on the subject of television.

In addition to Nader, participants include humorist Steve Allen, former astronaut James Irwin, National PTA President Ann Kahn, and Donna Deen and Dorothy Swanson, cofounders of Viewers for Quality Television. Much of what they say about television in the spots is positive and innocuous, but some of what they say is negative and trenchant.

That makes the campaign highly unusual in the swollen annals of network self-promotion -- upscale puffery for an America that already seems strangely, and irrationally, content with TV.

"Everybody in the United States watches television," says Frank Pintauro, the NBC vice president in charge of the project. "We wanted to have people offer their observations and ideas of what television is all about. We wanted to come across as being very audience-responsive."

One thing networks have always been criticized for is ignoring the protests of viewers, preferring by far the cuckoo trill of statistical data doled out by ratings services. These new corporate spots make NBC, currently the fattest and happiest of the three commercial networks, appear also to be open-minded and accommodating.

However, Nader thinks NBC's open-mindedness isn't exactly open-ended.

"It's really fascinating what they selected out of the 40 minutes that we filmed," Nader says. "They didn't use the real revolutionary stuff that I said. They showed an unerring instinct for taking the most bland of all the material." Nader says he agreed to take part because "I figured some of the things I wanted to say would come across," although at the time, "I couldn't quite figure out what their game is."

From Maui, Pintauro says NBC submitted transcripts of all the planned Nader spots to him once they'd been edited. "We sent him all the scripts, six or eight or nine of them, and he approved them all," Pintauro says. "All of those who participated had the right to kill whatever they wanted after we sent them the edited scripts."

The participants sat in front of a camera during their filming sessions and were asked leading questions. Their answers were later edited down into the 30-second spots.

Pintauro says the spots to begin airing on the 25th are only "the first wave" and that remarks made by Nader not included in his first four may be seen later. "We don't have to roll all these spots out at once," Pintauro says. There will eventually be 50 spots in the campaign, bolstered by print ads keyed to the "Tuned In" theme.

M.S. Rukeyser Jr., the NBC executive vice president whose Office of Corporate Communications came up with the campaign, says from Maui that Nader shouldn't judge the spots until he's seen all of them. "Everything we indicated to him will absolutely get played," Rukeyser says. He dismisses Nader's contention that NBC chose only the mildest remarks.

"Blandness was not on our minds," Rukeyser says. "We wanted a provocative spot that gets people's attention, and that's what we got. We didn't go to all this trouble to be bland."

How much trouble? NBC hired director Norman Seeff, who did those terrific Pizza Hut testimonial spots, to direct the filming of the NBC messages. They look much like the Pizza Hut commercials: simple, tight shots of the speakers, followed by a soft-sell identification of NBC. Very classy. Especially for a network.

Rukeyser says he has seen the corporate "American Television and You" spots that ABC has for some time been running -- with network executive James Duffy holding forth on how valuable TV is in all our little lives -- but wanted a subtler approach for NBC, one not so blatantly "self-serving."

An ABC spokesman said yesterday that later this summer, the "American Television and You" commercials will give way to an ABC public service project, "The Plus Campaign," designed to combat illiteracy in the United States, with spots referring viewers to appropriate agencies.

These corporate campaigns are separate from the networks' fall promotional pushes, which start late this month. As usual, the networks will try to evoke warm cuddly feelings about themselves with happy jolly spots. This year's are built around the themes "Together" (ABC), "Come Home to NBC" and, on CBS, "Share the Spirit."

Such campaigns, true to network promotional theology, say only positive things. That's the chief distinction of NBC's new corporate project: the inclusion of a few demurring views. Recruiting Nader for the cast was a controversial decision within NBC corporate circles. But the final editing of Nader's spots does seem to have softened, or changed the thrust, of some of his remarks.

In one spot, Nader says, "Look how much you can improve society just by giving people the news. Look what happened when British TV began to portray the famine in Ethiopia, and when U.S. national TV began to portray the famine. Can anybody deny that those portrayals on the news programs were the single most important cause of launching an aid mission to Ethiopia, to curtail the ravages of that famine?"

The spot ends there. But on the complete, unedited Nader tape, supplied by his office, Nader goes on to ask, "Well, how many other noble callings like that are forgone every year by Nielsen-minded television network executives?"

At one point during the filming, director Seeff asked Nader to think of more positive things he could say about TV. "It's hard to think of anything else," Nader told him.

Among other Nader remarks that do not turn up in the "first wave" of spots are these:

"It's clear that there is a lot of fraudulent television advertising."

"I'm not very enthusiastic about the evolution of the network nightly news."

"I think there are more violent acts on TV now than possibly any other time in its history."

Nader calls children's television "a very serious problem" and characterizes the network approach as "a massive and very cleverly designed program to get [children] to nag their parents to buy . . . the kind of food that's not good for them at that age and the kind of food that will predispose them later in life to get high blood pressure, cancer or other diseases."

These remarks, based on a screening of all the Nader spots, appear to have landed with plops on the cutting room floor.

All the spots are well produced, and all the participants come through, but one of the incidental revelations is what a skilled television communicator former astronaut Irwin is.

The mellow-macho communication prowess Irwin displays in these spots makes it all the sadder to read that he recently suffered a severe heart attack, though he is now listed in fair and stable condition.

Among the remarks that are included in the spots:

*"If you think television is doing anything wrong or having any kind of negative effect on your child . . . turn the damn set off for a while. Put the 5-year-old in your lap and read him a book . . . Human beings are more important than their images on television." -- Steve Allen.

*"Even if television had nothing but perfect programs on it, I think it would be important for people to limit the amount of television that young children watch." -- Ann Kahn.

*"When the quality isn't there, television can be mind numbing. When the quality is there, it can be breathtaking." -- Dorothy Swanson.

One of the Nader spots will be the one that kicks off the yearlong campaign during the broadcast of "Highway to Heaven" on June 25 -- at, according to the schedule, precisely 8:56:33 eastern time. What Nader says may seem "bland" to him, but when you consider that a commercial network has voluntarily given him the time and space to say it, NBC comes out looking good, and its campaign elevates the network promo to a tony new dignity.

"What needs to be done is to take all those frustrated great scriptwriters and programmers and producers," Nader says in Spot No. 1, "and give them greater elbow room, which all spells greater respect for the limitless potential of the American people to raise their expectations and demand a higher quality TV."

Oh it's not exactly the manifesto for a revolution in television. But to have the expression of such a view underwritten and broadcast by a TV network is some sort of encouraging sign. If it doesn't convincingly say "NBC cares about the state of television," it does convincingly say "NBC is no dummy."