In 1950, CBS REQUIRED its employes to sign a loyalty statement, and NBC instituted blacklists as a "business safeguard."

It was McCarthyism at its worst and powerful institutions at their weakest. Despite their power, the networks enthusiastically acquiesced in inneundos from self-proclaimed patriots who had little more than vivid imaginations.

The full story of the blacklists and the networks' own roles in ruining several broadcasting careers has yet to be told. nThe networks' refusal to look in the mirror forms the backdrop for Bill Granger's second novel (his first was a spy-thriller, November Man ). A victim of blacklisting is found dead in a seedy Manhattan hotel. In his forehead is a "small and mean" bullet hole, and in his typewriter is a blackmail note to Jeremy Heron, the nation's leading anchorman. Three decades earlier, Heron had lacked the courage to defy the McCarthyites and defend his now-dead friend.

In portraying the subsequent network battle over how to report the murder, Granger observes that perpetrators of the blacklists rarely believed they had done anything wrong; the people who suffered from conscience where those who opposed McCarthyism but never spoke out.

Granger appears to borrow from the movie Network as he stages mortal and moral combat between the aging Heron and Rudy Leibowicz, a young executive who worships the ratings. "Idealism doesn't sell cornflakes," Leibowicz proclaims. No one, not even Heron, disagrees.

To complicate matters further, Liebowicz is dating Heron's strong-willed, pretty daughter. She wants to protect her father, but can't resist Leibowicz despite his bland, unromantic directness. "I went to Acapulco with you, and God knows I shouldn't have left the office in January when ratings are starting to happen," Rudy points out during one of their many fights.

Sweeps -- the title refers to the special ratings periods when networks present their strongest programming -- avoids taking itself too seriously by treating television satirically: characters flip on their sets, and invariably a man "pouring axle grease on his head" or another ridiculous image flashes on the screen.

One warning: those who like to guess "whodunit" will feel manipulated by some of Granger's narrative devices and will find some aspects of the story, frankly, implausible.

Another new thriller, which has absorbed much from previous works is Sean Flannery's Eagles Fly . The author, whose Dremlin Conspiracy was the Mystery Writers of America 1979 nominee for best paperback mystery, appears to have adopted material form The Odessa File, The Manchurian Candidate , innumerable Kung Fu movies and various episodes of Mission Impossible and combined it with a few of Richard Nixon's favorite phrases to produce still another story of Nazi officials persistently dedicated to world domination.

Flannery's Nazis are aged and slow, yet they can kill at will, eavesdrop everywhere, corrupt the most initmate relationships and even subvert the entire U.S. government. Opposing them are a few lonely Jews and one German-American plastic surgeon: "Death was something they understood best of all," condludes an Israeli Nazi-hunter after giving the matter considerable thought. The plastic surgion manages to marry twice and lose both wives in the course of just one Nazi plot.

"Eagles Fly" are the code words used to activate a brainwashed fascist flunky who has been substituted for the vice president and then promoted via assassination to the Oval Office. His task is to initiate a Nazi-controlled world government convened under U.N. auspices.

The world's last hope is the surgeon, who decides to sneak into the United Nations and kill the bogus president. As a disguide, he performs plastic surgery on himself while standing in from of a mirror. Augmenting this new face with walnut dye, he poses as a representative from Botswana.

This could have been an exciting story. But Flannery makes the Nazis far too omnipotent and resorts to using monologues to dismass all the impossibilities.

"The only reason you got this far was because they're looking the other way, and because you haven't shaved, you're wearing a hat, and you stopped to get gas, eat or check into a motel only at night," one of the surgeon's friends summarizes for him.

The burden of such explanations drags Eagles Fly to the ground long before it can take off.