[Elecraft] [K3] Strange S meter behaviour

[Richard]

I calibrated the S meters on all my friends' and my own K3's with the 
XG2. All display S9 at 50 uV and S2-3 at 1 uV, which is normal.

On one of them, however, signals up to S9+20 dB seem reasonable, but 
above that, the S meter goes to hardly believable +50/+60 dB, for rather 
unrealistic reports... (50 mV at the antenna, from stations hundreds of 
miles away??)

This happens mainly on the low bands 160/80 meters.

Has anyone encountered this kind of issue?

73 de Richard - HB9ANM