was looking this up and found the following info...........
http://www.jfmg.co.uk/pages/equip/Radiomics/exempt.htmLicence Exempt
VHF
Band: 173.7 - 175.1 MHz
Available frequencies:
173.800, 174.000, 174.200, 174.400, 174.600, 174.800, 175.000 MHz
No. of mics: Typically up to 3 frequencies can be used together.
For example, 173.8, 174.2, and 175.0 MHz
Transmitter power: 10mW. (Up to 50mW permitted for body-worn pack)
Other users: Wireless microphones only
UHF
Band: 863.0 - 865.0 MHz
Available frequencies: From 863.100 MHz to 864.900 MHz
No. of mics: Typically up to 4 frequencies can be used together.
For example, 863.1, 863.7, 864.1 and 864.9 MHz
Transmitter power: 10mW.
Other users: Wireless microphones, domestic cordless headsets and loudspeakers
WiFi
Band: 2400 – 2483.5MHz
No. of mics: Manufacturers claim up to 70 frequencies can be used together.
Transmitter power: 10mW.