I have always felt that on 20m the KX-1 is much quieter in terms of
background noise compared with the 3 other bands. Having just bought a XG2
on ebay, I have been comparing receive performance at the 1uV level between
40m and 20m. There's no doubt that the s/n ratio on 40m is better by
several dB (not measured, so a subjective observation).
I have checked the alignment by adjustment of the trimmers 20a and 20b and
found that the tuning was already pretty much on the nose.
So the question is, is there anywhere else I should look? I have checked
both with and without the built-in ATU and reached the same conclusion.