garage years , boguing
Not sure if you have read my previous posts but you seem to agree it could be a shadowing of the antennas causing reduced received signal strength.But....
There is the issue that it has not always been a problem and apparently not related to recent maintenance , so in addition, I think there maybe a bonding problem causing the white noise that is only a problem when the received signal is low.
I have had an aircraft within 800 metres of the tower, line of sight and no signal. Rotated the aircraft a few degrees and I'd get 5s. The antenna was shadowed almost perfectly by the fuselage and other antennas.We could just hear the tower but they could not get squeak out of us.The aircraft was pointing directly at the tower antennasTrue story.
But given that this issue just cropped up gives reason to believe we have 2 conditions causing the defect.
If the handheld is not getting anything it maybe because it is not grounded to the fuselage which forms part of the bonding circuit.
If parts of the fuselage/ engine / cowls are not bonded there maybe circulating currents / potential differences causing the white noise.
Boguing if what you say is right the dizzy maybe a problem