I am confused by the channel bits (RF_CH) in register 0x05.
why is there a '1' in bit 1. I guess it can't be used and so the range is
00000010   - 2400MHz
00000011  -  2401MHz
00000110 (6) - 2406MHz ??????
00000111 (7)

The datasheet says the freq range is 2400 to 2525MHz but it also says Freq = 2400 + RF_CH MHz
Which therefore makes the first channel (00000010) 2402MHz