One more observation. The mounting bracket under the Tx is made of
mu-metal (place a small steel screw above and moving a magnet below has
no effect). So that in conjunction with the gaffer tape must be
something to do with minimising hum/hash, factory set on the
torquing-up. So any "undesigned" stressing via messing with the mounting
bolts or dropping the whole cab for instance, could destroy the mu-metal
effect and lead to a noise increase I suppose.