Here in Maryland the variation of magnetic north from true north is about
10%. So, when I have the compass sitting on a wooden fence post, when
the needle settles down I want it pointing at 350. The imprinted-on
needle on the compass is then pointing at 360 or true north.
Further north of Maryland, along the east coast of the U.S., the
variation would be greater. Further south, but still along the east
cost, it would be less. Further inland it would also be less.
On the west coast of the U.S. the variation would be to the opposite side
of 360 degrees. If you had a 10 degree east variation your floating
compass needle would point at 10.
One way of finding out what your local magnetic variation is is to
telephone your local airport. They should be able to tell you. You may
get the person who knows the answer on the telephone quicker if you call
a small airport.
73 - Rich Boyd, KE3Q
FAQ on WWW: http://www.contesting.com/towertalkfaq.html
Administrative requests: towertalk-REQUEST@contesting.com
Sponsored by Akorn Access, Inc & KM9P