21 + 21 = 42, close to the 30-40 degree pointing error you observe. Could
you have made the magnetic declination correction in the wrong direction?
The chart/map below indicates that at your location magnetic north is 21
degrees West of true north, i.e. that true north is 21 degrees to the
right/East of the compass needle.
http://picasso.ngdc.noaa.gov/cgi-bin/seg/util/gifrmt?map_29604.gif
At this site declination can be found by Latitude and Longitude:
http://www.ngdc.noaa.gov/cgi-bin/seg/gmag/fldsnth1.pl
73 George W5VU
----- Original Message -----
From: Carlos Augusto S. Pereira <py4ro@superig.com.br>
To: <towertalk@contesting.com>
Sent: Saturday, April 05, 2003 9:56 PM
Subject: [TowerTalk] Problems with my 2 el tribader yagi
> Dear friends,
>
> Some months ago I raised a 2 el. tribander Yagi. This antenna is
manufactured in Brazil but it is very similar to the Mosley TA-32 (you can
use it as a reference). I figured out -21 degrees of magnetic declination
according to my latitude and longitude which I used to correct the compass
bearing (correcting to the left - compass bearing minus 21). However I could
observe a difference of 30-40 degrees between the best signal and the right
bearing... For example... Europe is at 35 degrees but most of the best
signals happen at 70 degrees. The same happens with K?s, ZL?s etc. always
+30-40 degrees.
>
> There is not a balun connected to the antenna. The manufacturer claims it
is not necessary but some py friends warned me that this might be the
problem. What you guys think about this?
>
> The antenna has 4 guy wires now with the correct lenght (10 ft according
to the ARRL Handbook) and there is nothing higher than my antenna all
around.
>
> There is a link with a picture of my current setup:
>
> http://www.electril.com.br/revista.htm
>
> The page is in portuguese but what matters is the antenna picture at the
bottom.
>
> 73 and thanks.
>
> Carlos Augusto S. Pereita PY4RO
> www.qsl.net/py4ro
> E-mail: py4ro@superig.com.br
> _______________________________________________
>
> See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any
questions and ask for Sherman, W2FLA.
>
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