But then, I've forgotten a lot... I remember that most of the regular character voices also had roles in the serial, "General Comet of the Universe Patrol," with Mayor Plumpfront as Gen. Comet, Sparky as Captain Jupiter, and Princess Summerfall Winterspring as Second Lt. Millicent Ann(e) Millicent. But I can't for the life of me remember who played First Lt. Paul E. Goldbrick. 
I remember that the show originally originated in Cincinnati, but vaguely recall that it moved elsewhere for a year or so (New York? Chicago?) before returning. Remember Big Jon commenting from time to time about his beloved Red Legs?
In addition to "No School Today," the half-hour Saturday morning show, I was able to hear "Big Jon and Sparky" for 15 minutes on weekday afternoons-- probably Monday, Wednesday, and Friday-- during the 1950s in Walla Walla, Washington.
It was my privilege to see the pair perform at Walla Walla High School. Big Jon struck me as phenomenally tall but skinny, and I recall a simple marionette stage, rather than the more elaborate set described by Jay Johnson at his Big Jon and Sparky page ( http://home.netcom.com/~imajn8/jay/Sparky.html ).
But my memory is demonstrating its fallibility; I guess I'll have to order some tapes-- not for me, you understand, but for my five year old son, who needs to learn that there's more to broadcast entertainment than repackaged Japanese demonology.
