The strike of 39 members of the American Federation of Television and Radio Artists (AFTRA) continued yesterday against the Mutual Broadcasting System Inc. and Mutual Reports Inc. (the Mutual black network) with no sign of a move toward negotiation by either side.

The strike followed the firing by Mutual of correspondents John Hartge, John Meyer and Peter Gamble as well as Norma Morris, a tape editor.

Yesterday, Mutual President C. Edward Little charged the walkout Feb. 26 "constitutes a material breach of th AFTRA-MBS contract," signed recently between the parties which included, according to Little, a 13-month no-stike proviso.

Mutual, with 750 outlets around the country, continues to broadcast with nonunion and management personnel.

Peter Jennings, ABC's London bureau chief, is due to be a co-host of that network's upcoming prime-time magazine experiment, a la CBS' "who's Who," due to be tested in June . . . Jackson Bain has told Channel 4 officials that Jody Powell called to say how much President Carter enjoys thar WRC-TV promo depicting a Carter-like viewer voicing his approval of a fellow Georgian . . . well, that's what he says.

No sooner had ABC's "Challenge of the Network Stars," killed the opposition Monday night than CBS announced that on April 17 it will have a 2-hour prime-time "Celebrity Challenge of the Sexes" hosted by Vin Scully and Phyllis George . . . no names yet.

And out in Boulder, Colo., Mrs. Hilda Skinner has draped her TV set in a black cloth of mark "Turn the Television Set Off Week." Protesting what she calls "the death of decency on TV airwaves," she was upset last week by a series on the life styles of homosexuals that aired on a Denve station. She plans to remove the cloth in time for the weekend, however.

The Writers Guild this week signed a four-year contract with the networks and major program producers that gave writers an eight to 10 per cent salary boost. Current rates: $12,787 for a movie script; $5,000 for a half hour $7,400 for a full-hour TV script . . . CBS' ambitious "Minstrel Man" did poorly against ABC's lineup of JOhn Denver and Barry Manilow Wednesday night according to Nielsen overnights in New York, Los Angeles and Chicago. Even NBC's lineup of sitcoms and a Dean Martin roast out drew the story of black turn-of-the century vaudevillians.

Bill Leonard, CBS' top lobbyist in Washington, this week told the Federal Communications Bar Association here that lately "everyone with an axe to grind, a headline to grab, an ambition to fulfill or a cause to further finds a convenient whipping boy in television."

He said people forget a TV set has an on-off switch, adding that there should be one for the mouths of TV's critics. Leonard said he didn't think much of the food at the Army Navy Club that day, either.

Bob Lissit, former producer for ABC and PBS, has signed on as a consultant with Barry Jagoda at the White House . . . He's to see if the annaul $165 million worth of audio-visual programs turned out by government agencies and departments can't be cut back somehow . . . Peggy Ann Garner, who's been selling cars in Southern California the past five years, will appear soon in a "Police Women" episode.