When I visited Jack he was in an engineering equipment room off the stage floor.
You can see a bit of his work for a few seconds in this clip from a local newscast's behind-the-scenes story 25 years ago. (The whole five-part series is worth a good watch, too.)
Cool video! That's much as I remember it... the RCA77, the prizes on cards, and the delightful Jack! I don't believe audio was running their McKenzie sfx in that little room around the time I visited. Of course, now it's all vastly different: studios 2 and 4 share the same control room (one was ripped-out when the other was updated) as both studios are dedicated to a disappearing remnant of broadcasting, a big-budget soap, "Days of Our Lives."
In addition, that the entire Burbank facility was sold, and NBC is leasing back the property. The plan to build new studios across from the Universal lot was put on hold pending the Comcast ("Kabletown") acquisition. For those who remember studio 3 ("Squares", "SOTC", "Leno") it's sad to see it has now been ripped to the bare walls and is being used for storage! Leno is now in 9 and 11 ("TTTT2000", Louie-"Feud", and my beloved "Supermarket Sweep").
Randy
tvrandywest.com