New rules now in effect for operating wireless microphones and similar devices will restrict their use in certain bands of the spectrum currently used for television broadcasts. As a result, some equipment changes may be needed for local theaters, churches, schools, conference centers, sports stadiums and other users of such devices.
Wireless mics and similar devices are designed to tune and operate on certain frequencies known as "spectrum bands." Most wireless mics today operate in the various unused portions of the broadcast television bands, including both VHF and UHF channels. They can be operated on either on a licensed basis, for qualifying users, or on an unlicensed basis, open to all who use the appropriate equipment, provided that users follow the applicable rules for operation on designated spectrum bands.
To meet the increasing demand for wireless broadband services nationwide, the FCC recently auctioned spectrum that had been licensed to broadcast television stations operating on TV Channels 38-51. The results of the auction (completed in April 2017) will affect the availability of spectrum for wireless microphone operation on the 600 MHz frequencies. https://www.fcc.gov/consumers/guides/operation-wireless-microphones