With 21 months left before time runs out for passage of the Equal Rights Amendment to the Constitution, the National Organization for Women has hired a full-time coordinator and two field organizers to revitalize the campaign for support of three additional states necessary for ratification.

Carol Blum of Hollywood, Fla., past president of the Broward County, Florida. NOW chapter, will assume the $10,000-a-year Washington-based position of national ERA coordinator Tuesday.

The former legal assistant who attended Florida Atlantic University and once headed a local public relations agency, said her office was set up because NOW realized it "must take the major responsibiliy for getting ERA passed."

For the past 18 months NOW has been operating a state-by-state strategy, relying heavily on grass roots efforts to pass the amendment. But this year's failure to ratify the ERA in Florida and Nevada convinced leaders that their 60,000 members and resources could be used more effectively on a national basis. A resolution adopting that strategy was passed at NOW's national conference in April.

"President Carter made a lot of promises to women at the Democratic Convention but hasn't done a damn thing," says Blum. "People throughout the country are going to put pressure on the Democratic administration to get the machine that elected Carter to work for ratification."