squeal in radio?

Well there is a comparison, one works, one doesn't.

Why wouldn't the better radio work in the first place?

 

He does not say one works and the other doesn't he says one is more sensitive to engine,alternator,and other outside interference.
if properly grounded the Magnum will lose the noise and outperform the Midland!

 

Another old grounding trick is to actually ground the antanae to the frame of the truck.
Many of today's trucks have a plastic strip between the door hinge and cab,as well as ribbed bushings in the cab mounts that reduce grounding of the cab.
It should reduce some of the air noise.