Folks,
A little research produced Map and photo websites of your address, assuming
22 Attunga St
Woollahra NSW:
Say you want true north accurate to 2-4 degrees:
Use degrees, decimal degrees for your home location:
You can put your cursor right on your home, with the terraserver map, using
the decimal degrees..
33.8868
151.2459
http://www.terraserver.com/imagery/image_gx.asp?cpx=151.17724033462505&cpy=-33.874266831706215&res=8&provider_id=320&t=pan
http://www.whereis.com/whereis/mapping/zoomMap.do?mapIndex=4&brandId=1&level=3
Your magnetic declination there is 12.5 deg east, explained below:
Also by eyeball, look from your house to the following street intersections
and you will be very close
to true north:
Straight up Manning Road Very close to the intersection of Kiaora Road.,
Or, very close to the intersection of New South Head Rd and Bellvue Rd
73, DX, de Pat Barthelow AA6EG aa6eg@hotmail.com
>From elsewhere on the web:
>>>>True + Variation = Magnetic Magnetic+Deviation=Compass<<<<
Be careful. Variation and deviation are not always in the same direction,
and shouldn't always be added (assuming the plus signs above indicate
addition, rather than "plus the effect of"). Don't forget the old saw:
Variation West, compass best. Variation East, compass least.
In other words, if variation is westerly, then it must be added to the
desired true course to find the magnetic (so that the magnetic bearing is
greater than true or "best"). If variation is easterly it must be
subtracted from true to find magnetic (so that the magnetic bearing is
smaller or "least"). The same rule applies to deviation.
Down here variation is about 12.5 degrees East so it doesn't do to apply it
the wrong way.
Regards, Robert Bryett
Sydney, Australia.
mailto:rbryett@mail.com
>From: "AD5VJ Bob" <rtnmi@sbcglobal.net>
>To: "'VK2SN - Sean P Neylon'" <sean@vk2sn.com>,<towertalk@contesting.com>
>Subject: Re: [TowerTalk] Positoners Calibration to True North
>Date: Thu, 1 Dec 2005 21:45:40 -0600
>MIME-Version: 1.0
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>
>Try this link your lucky you have a compass I don't.
>
>http://www.satcure.co.uk/tech/compass.htm
>
>I have been trying to find a way for almost a year to
>figure true north (assuming that's what the logging
>programs use to do the long path short path thing)
> 73 fer nw,
>Bob AD5VJ
>
>10X# 37210, FP#-1141, SMIRK#-5177
>http://www.n5iet.com/
>Code may be taking a back seat for now,
>but the pioneering spirit that put the code
>there in the first place is out front of it all.
> > -----Original Message-----
> > From: towertalk-bounces@contesting.com
> > [mailto:towertalk-bounces@contesting.com] On Behalf Of
>VK2SN
> > - Sean P Neylon
> > Sent: Thursday, December 01, 2005 1:57 PM
> > To: towertalk@contesting.com
> > Subject: [TowerTalk] Positoners Calibration to True
>North
> > Dear all> >
> > I am just about to stand up my tower with everything
>ready to
> > go.yippee..at last..
> > I have Azimuth and Elevation Positioners M2 OR2800PDC
>and M2
> > MT1000 see www.vk2sn.com <http://www.vk2sn.com/> for
> > further details of my set-up.
> > My location is in the city of Sydney Australia S33 53'
>12.6'' and
> > E151 14' 45.4'' Grid QF56oc
> > To start with I will calibrate my poisoners to True
>North for
> > Nova and such., then once up and running, I will use the
>Sun
> > or whatever to further calibrate via the controller for
> > accuracy. But I want to at least get it close to
>accurate
> > before I put the tower up.
> > I also cant really re-adjust once it goes up, I have to
>pull it down and so on.its very heavy for one person, so Im
>hoping to get things sorted before it goes up,..plus its too
> > dangerous to climb and Im not one for climbing towers..I
>like my kids and want to see them live for a very long time.I
>
> > don't have the experience.smile.I'll do most things in
> > life..but not climb towers on houses..!!!
> > So the question is, I will use a compass to choose
>North, but
> > this is Magnetic North, to get True North, how many
>degrees
> > do I add or subtract from Magnetic North.or where can I
>find
> > this info, or how can I calculate it from my Sydney
>position
> > - because I gather its different for everyone re
>Latitude.
> > By the way, I hope this makes sense, the last time I had
>to
> > figure out where I was by using a compass was when I was
>
> > about 14 years old..so I would like some advice..
> > Please advise if Im doing this right, or is there a much
>
> > better and easy way to sort/calibrate this situation..
> > Thanks guys,
> > Sean Neylon
> > Sean P. Neylon VK2SN QF56oc
> >
> > Cell Phone: ++ 61 413 747 276
> >
> > web: www.vk2sn.com
> >
> > email: sean@vk2sn.com
> >
>
_______________________________________________
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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