[TowerTalk] Positoners Calibration to True North

[W0UN -- John Brosnahan]

Local Solar Noon

Go to your newspaper weather forecast column (or almanac section) and 
get local
sunrise and sunset times.

HALF WAY IN BETWEEN is local solar noon.


Or go to www.weather.com then type in your zip code and then click on 
sunrise/sunset
for your local sunrise and sunset times.

HALF WAY IN BETWEEN is local solar noon.


Or go to http://www.weatherunderground.com then type in your zip code and then
scroll down to the Astronomy section for sunrise and sunset times.

HALF WAY IN BETWEEN is local solar noon.


Plumb a stick and at the calculated time the shadow is true north.  With a
long enough stick and a bright sun you should be able to obtain true north
with greater than one degree accuracy.  This is about the same accuracy
you can obtain using Polaris (the North Star) without compensating for its
3/4 degree offset and subsequent rotation around the true north position.

--John  W0UN