I believe this is an extract taken from a special talking about unsold pilots. That is indeed what this Mandrake is. The 1979 production from Universal aired on NBC January 24, 1979.
Anthony Herrara plays the titular magician, who dates back to 1934's King Features comic strip. This somewhat snide clip doesn't highlight the rest of the cast: BOTNS favorite Gretchen Corbett, James Hong, Robert Reed, and Harry Blackstone!
The full movie is available on YouTube if you are interested.
