[Elecraft] K3: transmitted RF feedback with condenser mics?

[Brian Machesney]

I am getting transmitted RF feedback into the K3 when running high power
with a headset that uses a condenser element. With an otherwise identical
setup, I don't have any problems with either of my two headsets that have
dynamic mic elements, using either the front- or the rear-panel mic jacks.

I hear the distortion in the K3's own monitor, but I have confirmed the
distortion using my K2 as a second receiver (1" wire in the ANT jack, RF
gain near zero, ATT on to prevent front-end overload) and with on-the-air
tests with stations hundreds to thousands of miles away.

The problem headset is designed for aviation use and, as far as I can tell,
uses a shielded mic cable.

Has anyone else had and resolved this problem?

-- 
73 -- Brian -- K1LI