[Elecraft] KX3: Low frequency thumping sound in receive audio

[James Austin]

I have a KX3 in which I hear a low frequency thumping sound in the receive
audio, 1-2 Hz. You can barely hear it if the antenna is connected and is
far more apparent if the antenna is disconnected.

I can mitigate or eliminate the noise by loosening the screws that hold the
two halves together.

I assembled the radio as a kit and it includes the antenna tuner, 2m
module, and paddles. The radio otherwise works fine, but something seems to
be off kilter when putting it together and tightening the screws.

Does anyone have any suggestions on what to look at? I didn't see anything
obvious.

73, Jim KA2RVO