If you are caught using a wireless microphone within the 600 MHz range, you may be subject to fines. The amount of the fine will depend on the severity of the infraction and whether it was a first-time or repeat offense.
Wireless microphone devices operating between 614-616 MHz and 653-662 MHz are available for use. These frequencies are not available in all cities and states. Operating a wireless microphone within the available frequencies does not mean you will receive reception. Please check your local area to determine frequency availability.
For example: Houston, TX has a radio station 104.1. But 104.1 does not work in New Orleans, LA. The same goes for wireless frequency signals. If your area does not have that 'channel', your wireless microphone will not work.
To determine if your wireless microphone system operates within the 600 MHz range, you can check the FCC's website for a list of affected frequency bands. You can also check the manual or specifications for your microphone system, as it should indicate the frequency range that it operates in.
If you are not sure whether your microphone system is operating within the 600 MHz range, it is best to err on the side of caution and assume that it is. In this case, you should stop using the microphone and consider purchasing a new one that operates within a different frequency range.
Fore more information: visit FCC https://www.fcc.gov/consumers/guides/operation-wireless-microphones