This commanding, heavy-set actor, producer and director of radio, film and TV since the 1940s may now be best known as TV's "Cannon" (CBS, 1971-1975), a hefty and quietly methodical detective--and an impressively smooth ladies man. To younger viewers, Conrad may always be the rough-edged, cantankerous, cigar-smoking district attorney (and, after retirement and a hiatus, an unshaven P.I. in Hawaii) on "Jake and the Fatman" (CBS, 1987-88; 1989-92). However there was a lot more to this big man's long showbiz career.With his deep rich speaking voice, Conrad was a highly accomplished and prolific