[Elecraft] 10 meter SSB audio distortion

[Stuart Rohre]

Is the mike cable shield grounded to the radio mike connector shell and thus
the radio case?
It should be to preclude RF effects.  It sounds like you have an unbalanced
or end fed antenna?
If that is a case a dipole/ doublet will be a better choice in that location
where you have some RF coupling back into the shack.  End fed antennas are
often a problem creating RF in the shack, as are coax fed doublet/ dipole.
Make sure the feedline is not an odd multiple  of a quarter wave, ie 8 feet
at 10m is a quarter wave and sure to cause a problem, and any odd multiple
like 24 feet, 40 feet, 56 feet, etc.
-Stuart
K5KVH