thanks for the replys!
the mics are all fine and the transmitters/receivers are good - cannot recreate the problem with mic inputs 1-3 with the same gear..
the limiter settings seems to have no effect when changed the same noise occurs - at the moment its on across all isos on hard knee at 18dbu
but have played around with dropping the limiters down, using soft knee etc same noise..
its happening at the isos - that file i uploaded is the input 4 iso raw
if anyone else drives their 4-6 gains up do you get the same noise?
even when the trim is at +8 or +6 wherever it is, whenever these inputs peak/clip/get close to clipping this noise occurs