This is the Broadcast FAQ section of
The Broadcast Archive

There was an earlier era when more than one station in a market was owned by the same company. Often, they were NBC affiliates, with one stations running NBC Red and the other NBC Blue. When one operator was required to run them and keep them "separate" ... well, you know what can happen.

On February 12, 1931, the Papal address on World Peace was carried on the NBC Blue Network. At the same time the Red Network was running a remote light program "The Shell Ship of Joy." As "The Shell Ship of Joy" concluded, Cecil Underwood flipped the wrong switch and cut into the Pope's talk with the words: "This past hour of fun and nonsense has come to you over KPO, San Francisco."

By the way, it WAS NOT Uncle Don that made the "famous" remark on the kiddies show. (Actually, many of the "bloopers" you've heard on the Kermit Schafer records and tapes were recreations and in many cases, fictional.
It is also untrue that Harry Von Zell announced "President Hoobert Heever" just before a live presidential address. (This is another canard from Kermit Schafer.)

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