Except (Score 1, Informative)

that's exactly how wireless microphones are deployed in the field.

In heavily saturated markets, the wireless mic frequency may sit between a TV video signal and the same channel's audio signal.

At least until things go all digital, then audio and video are muxed into one square wave leaving no room to stick a mic signal. This exasperates the dilemma facing wireless mic operators.

And yes that little PDA can easily wreak havoc on a Broadway show, NFL broadcast or any other production. That's why we regulate the spectrum...devices operating on the same frequency will interfere.