[Antennas] Using GeoClock To Find True North

Mon, 18 Feb 2002 18:34:15 -0800

I f  you want to use this approximate method you have to use the points 
when the shadow is at the same length, before and after approximate 
noon.  Noon local should be when the shadow is the smallest.  That is the 
way I remember doing it when I was a kid.

Chris opr VE7HCB

At 06:17 PM 2002-02-18 -0500, Don Havlicek wrote:
>No, no, no .... if the two marks were made at 0900 and 1000, then N/S
>line would be somewhere close to NW/SE !!!!!
>
>Better to do this:
>1.  Drive the stick into the ground and mark the end of its shadow at
>some time in the early morning, recording the clocktime.
>2.  Mark the the end of its shadow again at a time which is the SAME
>AMOUNT AFTER noon that the first mark is BEFORE noon.
>3.  Now do what you suggest:  the perpendicular bisector of the segment
>between the two points is APPROXIMATELY the N/S line.
>4.  Better way:  Use the North Star as someone previously mentioned.
>5.  Best way:  Use a compass and apply the correct declination
>correction.
>Don
>N8DE
>
>Jim Clark wrote:
> >
> > This sounds like a job for Indiana Jones or Laura Croft. (I'll take
> > Laura!)
> >
> > Egyptian compass:
> >
> > Pick a nice sunny day.
> > Drive a stick several feet long into the ground straight up.
> > Mark the end of its shadow with a small stick.
> >
> > About an hour or so later mark the shadow's position again.
> > Draw a line between these two points.
> > A line perpendicular to that line is north / south.
> >
> > Jim, N5QL
> >
> >
> >
> > - - -
> >
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>- - -
>
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