Broadcasting

If you see NBC News anchor Tom Brokaw on PBS next summer, your TV isn't broken. NBC and the Public Broadcasting Service last week announced an unprecedented partnership for the 1992 presidential conventions. The rivals will jointly produce programming for PBS. Brokaw will appear on PBS with Robert MacNeil and Jim Lehrer, and solo on NBC. The deal provides NBC with a graceful way of covering the conventions without sacrificing lucrative entertainment shows, since its own coverage won't begin until 9:30 p.m. With viewership dwindling, the conventions have become an expensive duty for the networks. Still, they are loath to offend politicians, who regulate broadcasting.