how to use sun or compass for true south

remlap

How is it possable to find true south useing the sun postion is it at 12 o'clock British summer time or 1 o'clock ? Also can someone explain how to use a magnetic compass to find true south takeing into account magnetic devation from a given loaction in the UK.

Burnham Beech

A compass is accurate to about 3° at the moment for most of the UK.

Unless you have a very expensive compass that's within the accuracy of the compass and the ability to line up your dish with the compass.

Satslut

Goto http://www.ordnancesurvey.co.uk/oswe...isc/north.html

all will be revealed

Happy-Buddah

Magnetic north is somewhere in canada at the present time. Hence the three british ladies racing to be the first female team to reach it.

The sun is due south, in the UK at 12 noon GMT (1pm BST) if you are on the zero meridian. For each degree off of that the sun appears to have moved 4 minutes in time.
ie, I'm at 1*east so my due south is 11.56GMT or 12.56BST. For some one in Poole, 2*west, the sun would be due south at 12.08GMT (13.08BST). For someone in Fishguard, 6*west, the sun would be due south at 12.24GMT (13.24BST) etc etc. The above applies to the UK, where we have one time zone.
H-B

transpetaflops

You also have to correct for the Equation of Time which can differ more than 15 minutes.
http://www.sundials.co.uk/equation.htm

Low Profile

Point the hour hand at the sun (use a vertical stick or object to cast a shadow if you have difficulty), split the angle between the hour hand and the 12 oclock position to give a north / south line.
I've used this method to help in setting up satellite dishes all over Europe - from Norway to Portugal without a compass.

Happy-Buddah

Useing the sun at noon (GMT) is a close enough approximation and starting point. Agreed that "the equation of time" will make a difference, at a minimum on 16th April and maximum on 5th May (at this time of the year) but as stated above "it's a starting point and we all have had to tweak our dishes for maximum signal strength.

H-B