It is now illegal to operate wireless audio in much of the 600 MHz band.
In 2017, No Film School reported on the auction of the 600 MHz frequency band by the FCC. The auction enabled telecommunications and cable companies to use the coveted frequency range to expand their own networks. This reduced the radio spectrum for sound operators in the film and television industry in both the USA and Canada. The ten-part transition phase ended today, July 13, 2020. Now, any operator who uses wireless audio in the 600 MHz spectrum, with the exception of some specific frequencies, can be fined if intercepted.
The FCC's auction of wireless bandwidth is nothing new. The independent U.S. government agency sold the 700 MHz spectrum ten years ago, and since billions of dollars may be earned, the FCC is likely to continue auctioning more radio spectrum to companies willing to pay the price. The sale of the 600 MHz frequency band further limits the available frequency channels over which wireless audio can transmit sound. Both 700 MHz and 600 MHz are in demand because wireless devices can spread through walls more efficiently.
The two key dates during the transition period were October 13, 2018, which prevented companies from buying, renting, or selling devices that worked in the 600 MHz band, and the end of the transition period that is now. However, there are exceptions depending on whether you are a licensed Part 74 user or an unlicensed user. The available frequency channels fall in the guard band and the duplex gap of the 600 MHz band.
- 614-616 MHz: 2 MHz (unlicensed operator)
- 616-617 MHz: 1 MHz buffer (not available for use)
- 652-653 MHz: 1 MHz buffer (not available for use)
- 653-657 MHz: 4 MHz (exclusively for licensed operators)
- 657-663 MHz: 6 MHz (unlicensed devices and white space devices (WSD))
There are other limitations to transmitting audio at these frequencies, including a 20 mW power limitation for wireless devices and 40 mW for white space devices (WSD).
Technically, you can still use limited-capacity wireless audio in the 600 MHz frequency band, but this doesn't guarantee clean channels. Radio interference can still occur, with critical dialogue being trampled on by noise. These small rooms were mostly left open to ENG news teams reporting on site.
Sound recorders should not use or buy wireless audio with a frequency of 600 MHz, not only to avoid a fine, but also because of possible interference with the operation of a device. You can find out if you have a 600 MHz wireless device by looking at the menu or by contacting the manufacturer directly.
Many companies, including Audio-Technica, Lectrosonics, Shure and Zaxcom, offered various trade-in programs during the transition period. They are unlikely to honor these programs now, but it can't hurt to check them out. Please note that this only affects wireless audio in the United States and Canada. Other countries regulate wireless audio differently.