TV RATINGS

CBS sent Dan Rather to Washington last week to anchor live coverage of the Iran-contra hearings, but the new locale didn’t help the “CBS Evening News” in the Nielsen ratings. The “NBC Nightly News” won for the 13th week in a row, ABC’s evening news was second and CBS dropped to third again. Meanwhile, ABC has been getting the biggest ratings for its live coverage of Lt. Col. Oliver L. North’s testimony, at least in the biggest TV markets. On the entertainment side, NBC’s winning duo--”Family Ties” and “The Cosby Show”--finished one-two in the Nielsens, followed by “With Intent to Kill,” “Murder, She Wrote,” “Growing Pains,” “Cheers,” “Shattered Vows,” “Who’s the Boss,” “60 Minutes” and “Valerie.” Three CBS shows, “West 57th,” “Dallas” and “Space,” occupied the Nielsen cellar. The complete Nielsen list appears on Page 11.