WIP as I go along. Don't follow until complete, you need to back up calibration data etc first.

v6.02.00.0001 enforces “FCC Narrow Banding” which requires a Software Key to use channels wider than 12.5kHz, which we don't want. Note that the latest f/w available from the Tait groups.io page is v6.02.00.0002 but the filename is truncated, so avoid it. Instead go for V-6.01.00.

Note “TM8200 bodies and High-Tier heads must both have matching Firmware versions in order to operate correctly when assembled”