WORTH NOTING ON TV

* THURSDAY

Viewer Call-in (C-Span, 6:30-8 p.m., EST): The channel's daily program giving viewers a chance to speak directly with figures active in public affairs. FRIDAY

Time Machine (A&E, 8-9 p.m.): This edition, hosted by Jack Perkins, offers the North American premiere of ``The Secret Life of Chairman Mao,'' a revealing and controversial BBC program that aired on Britain's widely viewed ``Timewatch'' series.

Try to overlook its tab-TV title and remember that its subject is the late Chinese dictator Mao Zedong, certainly among a handful of the century's most important political figures. His image and record were almost totally controlled in China during his reign beginning in 1949. Outside China, not a lot more was revealed about Mao the man.

The Chinese government requested the program's cancellation, and it's not hard to understand why: It deals with seamy aspects of Mao's private life that may repel some viewers. Mao's personal physician, Li Zhisui, now living in Chicago, talks about Mao for the first time and alleges many affairs with women. Some of Mao's peculiar personal habits are examined. The program also recounts failures in Mao's domestic policy and his hostile relations with Soviet leader Nikita Khrushchev.

But Mao's historic successes are recounted, too: Henry Kissinger, Richard Nixon, and Edward Heath comment on Mao's campaigns against the Japanese and the founding of the People's Republic of China in 1949.

World Professional Figure Skating Championships (NBC, 9-11 p.m.): Now that the United States Figure Skating championships are over - won by Tonya Harding amid high-profile news coverage of the attack on her rival Nancy Kerrigan - fans of the sport can whet their appetites for the Olympics with taped highlights of last December's professional event in Landover, Md. The special is Part I of NBC's coverage. (Part II airs Jan. 28, 9-11 p.m.)

Please check local listings for these programs.