The radio dosent need to be conected to the ground. It will work fine without it.
The fact that the atu isnt tuning it is your problem.
Are you sure the control wires to the atu are right?
If you tune the radio right down to the broadcast band and see if you get anything there 1.548 (I think? or it could be 0.1548) should be radio city (or whatever it.s called
Why did you go for a whip rather than a backstay? I doubt that is your problem i was just wondering why?
Rob