Configuring audiovox GMRS1072CH walkie talkie
With the issue of 240V if the charger has not a Voltage switch, you will need to find another charger/transformer with the same Voltage/Amps ouput that works with 240V.
For Vox operations, this feature works independly form channel, you should choose the channel# and code # first, to match both radios, and get them communicate, then the Vox feature.
In Some radios the VOX feature works with an external audio accesory, in other radios works with out it.
Basically if this radios works without it, you should see that the radio transmist by itself when you speak direct to the radio, and stops transmiting 1 or2 seconds after you stop talking.
Good Luck. Read More At : Icom IC-F11 5W 16ch VHF transceiver 2-Way Radio...