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azimuth indexing of beams

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Subject: azimuth indexing of beams
From: (Fred Hopengarten)
Date: Wed, 08 Jan 1997 12:10:32 EST
Fred Hopengarten, K1VR
Six Willarch Road * Lincoln, MA 01773-5105 * 617/259-0088
Big antennas, high in the sky, are better than small ones, low.

On Tue, 7 Jan 1997 12:34:52 -0700 al511@freenet.uchsc.EDU (Robert Neece)

>I have read with interest the several postings concerning
>ascertainment of true north.  I myself use a method different
>from those described so far.
>My method of indexing rotators, masts, and rotatable antennas to
>compass headings does not depend upon a determination of 
>true north and, therefore, avoids compasses, clocks, calculations, 
>sun shadows, and the like.
>I simply use a landmark of known (and constant) azimuth, and orient 
>my antennas on the mast by sighting them against the landmark.  Works
>wonderfully at the top of the tower, can be used on cloudy days, can
>be used at any time during daylight hours, and is fabulously accurate.
>In my own situation, a volcanic butte is visible near the
>horizon from the top of my tower.  I obtained USGS 7.5 minute 
>maps that cover my QTH and the butte.  (It takes two maps for me
>because the butte in question is on the quadrangle east of the one 
>contains my QTH.)
>An examination of the maps reveals that the butte is very nearly due 
>of my QTH.  I calibrate the rotator indicator as described in the 
>and then set the rotator exactly at north.  I then climb the tower and 
>sight along the antenna element nearest the mast.  With the 
>bracket somewhat loosened, I rotate the antenna on the mast until the 
>element points straight at the butte.  (With a yagi, of course, I
>position the antenna so that the reflector element is on the south 
>of the mast.)  
>Tighten the boom-to-mast clamp.  Perfect azimuth alignment 
>This method is easiest to use if one can find a landmark at one of the
>principal compass points:  N E S or W.  A building, another tower,
>a geological feature, or anything else that is visible, and the
>location of which can be identified on the map, will work FB.
>Bob, K0KR and K7KU


        You are a smart fellow.  I use a minor variation on your system. 
I have determined with great accuracy that my three guy wires heading
"East" are at 110 degrees true.

        I set my rotators to 110 degrees.

        I climb the tower and make all rotary beam booms parallel with
those guy wires.

        Even on the foggiest of days, when I cannot spot landmarks, I can
line up my booms with those guy wires.

                                Fred K1VR

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