# Re: AHA! My Rx Problem Explained!

```Another good way to determine azimuth and altitude at your
QTH is use the position of the Sun and Moon. The Web site

http://www.sweethome.de/giesen/SME/index.html

has a Java applet that calculates the position of the Sun
and Moon in the sky for any location on earth for each hour
of the day and displays it relative to the the horizon. You
may also calculate the altitude and azimuth for any position
on earth at any time. You can calibrate any El-Az system by
sighting the sun or moon at different times of the day. This
is a method used by sailors to calibrate the deviation of
their compass by aligning the long axis of the boat with

Jack, K2BMI

On Tue, 17 Jul 2001, Estes Wayne-W10191 wrote:

> Hasan wrote:
>
> Today, I bought a compass. Guess what? I wasn't even close. Where I thought
> I was pointing at 108 degrees with a nice 8 deg squint....well, I was
> pointing at 120 degrees and 108 was in the middle of my TREE. Where I
> thought I was pointing at 135....I was pointing a lot closer to 150 deg. In
> fact 135 was closer to being in the middle of ANOTHER TREE!
>
> Wayne replies:
>
> Don't forget that your compass points to magnetic north which is not usually
> the same as true north because the magnetic north pole is NOT located at the
> geographic north pole.  Make sure you correct any compass readings with the
> magnetic declination for your specific location.  For instance, Boston has a
> magnetic declination of 16 degrees West (magnetic north is actually at 344
> degrees azimuth).  Seattle has a magnetic declination of 20 degrees East
> (magnetic north is at 20 degrees azimuth).  The magnetic declination is
> close to zero in Wisconsin, Illinois, western Tennessee, and Alabama.
>
> Here's a site with blurry magnetic declination maps for most regions of the
> world:
>
> http://www.geo-orbit.org/sizepgs/magmapsp.html
> <http://www.geo-orbit.org/sizepgs/magmapsp.html>
>
> The Canadian government has a nice site where you enter your lat/lon and
> your magnetic declination is computed.  You can even see how it changes over
> the years as the magnetic north pole drifts around Northern Canada.
>
> http://www.geolab.nrcan.gc.ca/geomag/e_cgrf.html
> <http://www.geolab.nrcan.gc.ca/geomag/e_cgrf.html>
>
> Fortunately for Hasan, the magnetic declination is relatively small in Iowa
> - less than 5 degrees.  My magnetic declination in grid EN62af (Chicago
> area) is only 2 degrees 22 minutes West.  Back in 1980 my magnetic
> declination was only 0 degrees 2 minutes.
>
> Wayne Estes W9AE
> Mundelein, IL, USA
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