ICOM IC-7100 audio noise / interference problem and solution (also affects IC-7300)
In this video, I demonstrate parasitic noise at certain frequencies. The noise is generated by the PWM audio power amplifier inside these units. It essentially creates interference in the lower end of the HF spectrum. I demonstrate a solution I came up with, which is to replace the PWM audio power amp with a linear one. Not an easy modification, but not too difficult either.