[ARC5] Mil Headset noise blanker

[David Stinson]

I always open the Sidetone lines or use series attentuation.
Haven't spent much time on this issue.

One thing you *can't* do:
 a typical clipper across the sidetone leads.
When it clips, that "short" is reflected from the Sidetone
winding in the Mod transformer back to the rest of the 
windings and fouls the transmit audio.

73 Dave AB5S