Adjusting for Magnetic declamation.

[videobruce]

My offset (if that is the correct term) is 10.5 degrees E
Does this mean I add 10 to a compass reading or subtract it from that reading?
IOW's if I set the compass so the needle is pointing north, do I rotate the dial clockwise so the pointer is at 350 degrees, or do I rotate it counterclockwise so the pointer is at 10 degrees?

[pmb1010]

Let's assume you're at the northern tip of Virginia, on the map at the bottom of this page:

http://www.sadoun.com/Sat/Installati...Calculator.htm

The red line shows "-10" but at the bottom, in blue it says "ADD TO AZIMUTH FOR COMPASS READING". That is the important part.

So this is what you do.

Hold out your compass, rotate until the N lines up directly on N.
Leave it there.

Now, find your calculated azimuth, (lets assume it to be 175 degrees) and you need to ADD 10 to that number. So you'd line up all your dish, motor, etc all to 185 degrees on the compass pointer.
Easiest way to do that is have someone walk out into yard, line up by eye along the compass, and place a stick in the ground at the 185 heading direction.

[videobruce]

Or to put it another way, if the pointer is on 'N', true north is at 10 degrees, correct?

[pmb1010]

I suppose...

North isn't referenced that I can think of, so I really never gave it any consideration in that resepect.

Everything seems to be discussed as west, east and south when fooling around with this satellite stuff...