All the negative publicity Arizona Gov. Evan Mecham has been receiving in news columns and elsewhere on this page in the "Doonesbury" strip has proved costly to his state. Just last weekend, the Radio & Television News Directors Association decided to try to find a way to change the site of its 1988 convention, scheduled for late in the year in Phoenix.

Robert Vaughn, director of the association's conventions, said the board surprised the staff in issuing an order to look for an alternative site as soon as possible, deploring, without naming Mecham, the inhospitable atmosphere "inimical to equal rights and First Amendment rights." The Radio & Television News Directors group is not a small one to lose. Vaughn said about 2,800 people taking up 2,000 hotel rooms for the 1987 convention last week in Orlando added about $3 million to that city's economy. An employe of the Phoenix convention bureau here, who asked not to be identified, estimated that Mecham has cost the state $23 million in convention business. Mecham, whose publicity problems began after rescinding the state holiday in honor of Martin Luther King and making a series of controversial statements, has described the "Doonesbury" depiction of him as "brutish and grotesque," adding that he has decided not to sue. An official of Universal Press Syndicate, which distributes "Doonesbury," said, "If people like John Mitchell and Frank Sinatra can't sue, then there is no way Mecham can sue." Both Sinatra and Mitchell have been targets of the pen, ink and wit of cartoonist Garry Trudeau.

Out and About

Big, burly, bearded John Riggins may no longer be smashing through those equally massive linemen on Sunday afternoons at RFK Stadium, but he still attracts attention, or knows how to get it. He stalked into Duke Zeibert's for lunch yesterday in cowboy hat and boots, and before his long lunch was over, the affable former Redskins fullback had challenged Sam Refiddy, one of Zeibert's longtime employes, to an arm wrestling match. Refiddy reportedly is 72 and Riggins is 38, but Refiddy held his own, though finally losing two contests as Riggins' boisterously happy shouts reverberated throughout the restaurant. The scene attracted most of the lingering diners and lured Zeibert's staff into the room to witness the competition ...

Brown University is expecting Amy Carter to return to the school following her suspension this summer for neglecting her studies while taking part in political activities. The daughter of former president Jimmy Carter was quoted in the October issue of Good Housekeeping magazine as saying that her devotion to political causes "comes from having a best friend who tried to kill herself. Something like that can really change the way you look at the world." She gave no other details about the friend ...

Now that former big band leader Woody Herman's entertainment world friends have stepped in to help him pay his rent, a congressman is attempting to come to his rescue on the tax front. Rep. John Conyers (D-Mich.) announced yesterday that he plans to introduce a bill in Congress next week that would wipe out Herman's $1.6 million tax debt ...

Hospital Report: Deputy Commerce Secretary Clarence Brown remains in satisfactory condition at Sibley Memorial Hospital following removal of his left kidney last week. He is expected to be released this weekend or early next week. Brown has been serving as acting secretary of commerce since the death of Malcolm Baldrige in July ...

Those funny postage stamps with the upside-down candlestick and off center halo have proved to be a hot item indeed for collectors. The block of 18 misprinted $1 stamps originally purchased by CIA employes sold for $900,000 to John Reznikoff, a Connecticut stamp dealer. And experts are predicting that the ultimate value of the misprints could reach $115,000 each. CIA workers had apparently bought the stamps along with normal office supplies and, noticing the misprinting, replaced them with regular stamps and sold the inverts to a New Jersey dealer. CIA officials have declined to comment on reports the agency is investigating nine employes for profiting by selling the stamps ...

Dick Smothers has decided that while he and his brother Tommy are in town this week performing at Blues Alley, it might be a good opportunity to have his new daughter, Sarah, christened. Dick Smothers and his Washingtonian wife, the former Lorraine Martin, have scheduled the christening for this Sunday at St. John's Episcopal Church in McLean ...