By the way all, be aware that in many parts of the country, the magnetic field lines have shifted enough to change runway numbers. my home field (KCOE, Coeur d'Alene, Idaho) had to renumber the runways recently - Rnwy 1/29 became 2/20 and 5/23 became 6/24. Be sure to check whether the airport where you do your calibration has changed recently and if field compass rose (if there is one) has been updated to match it or you will mis-calibrate your compass.

Dan Schaefer