Figure this one out:

When I depress the brake pedal I hear a faint high pitched "whine" from the
radio. It's pitch (frequency) changes with pedal pressure (higher with more
pressure), and only happens on AM stations. Unfortunately, my favorite
sports radio stations are AM so I hear it often.

It didn't change with a new radio last year, and I do have LED brake lights
and the GW high mounted LED brake light. Brake light switches have not been
replaced.  Whine was there with the 1.9 engine and is unchanged with my '93
Subaru 2.2 engine conversion. I have not switched the bulbs back yet, but
I'll give that a try and see if it goes away.

It's just a nuisance, but I'm stumped, particularly by the change in
frequency with pedal pressure. Any ideas why LED brake lights might cause
this? Maybe install a capacitor on the radio like this?
https://www.amazon.com/PAC-CSS12-Passive-Filter-Capacitor/dp/B000CEDZBA

Stuart

'85 Westy