Ditto. I have Heil microphones on all of my mobile ham radios.
My Icom 7100, with supposedly a 100 watt transmitter only put out 30 watts until I replaced the stock mic with a Heil studio type mic.
Then it put out the full 100 watts.
The interviews with him on Youtube are well worth watching.
RIP, a great man.
Bkbm