Sounds like you are getting yourself tied up in knots, its happened to us all.
There are 3 stages to using the radio
a) the null thing in init.sqs
b) creating the radio trigger by use of another trigger
condition: !alive jeep
on activation: 1 setradiomsg "make this work"
c) using the radio trigger
activation: Radio Alpha
on activation: hint "this works"
as ever, syntax not guaranteed
Keep trying, you're nearly there.