"RF carrier frequency ranges - 863 - 865 MHz"

This is the de-regulated part of channel 70 set aside specifically for radio mic use, and is unlikely to be sold off in the forseeable future.

It is possible to use six systems within that range, but they may be susceptible to inter-frequency interference problems, so the recommended spread of four frequencies is advised.

De-reg frequencies channel 70 - 863.000 to 865.000

Recommended spacing:

863.100 MHz
863.500 MHz
864.300 MHz
864.900 MHz

Six channel function:

863.100 MHz
863.400 MHz
863.750 MHz
864.225 MHz
864.550 MHz
864.975 MHz