[Heathkit] HM-2140 Question

[Rick Markey, KN3C]

Has anyone seen a procedure for calibrating the remote sensor for the 
HM-2140?  That was provided as a "sealed" unit and was calibrated at the 
factory.  I own three of these meters, and the last one had a problem 
when I bought it, that required replacing a few components in the remote 
sensor.  After the parts were replaced, I noticed some difference 
between the repaired unit, and the other two which work normally.

Thank you,
Rick, KN3C