Magnetic Declination – True, with a Compass
GP,
As I wrote in my PM to you, I apologize for the incorrect Link to TopoZone, the correct one is
http://www.topozone.com/
I had not checked the Link in a while, and find that you need to type in your City and select the State, then it will direct you to the proper Map, where you can read your Magnetic Declination (MD) at the bottom right area of the page. It appears in a little Avatar they use for showing the Declination between True, Magnetic and Grid. You (or others) might click on the Avatar, and read the information, it’s interesting.
Example:
If you type in Houston, then select “TX”, then click on “Place” which is over “Houston”. You will see a MD of –4.062°, I offer this, just so you’ll know you’re headed in the right direction, and able to identify the Avatar/MD I’m referring to.
With proper penance for my error, I looked up the information for you, and find that YOUR location at San Jose, CA. has a MD of (minus) –14.953°. I selected the link for Santa Clara, since it was nearer your Wlong. You can move the Map with the arrows to your exact location, but, that would only change the Wlong less that 0.1°. Not an appreciable amount. The Link you gave for the Microsoft Map, seemed a little more complicated to get, but, that’s your choice.
IF you have an adjustable Declination Ring on your Magnetic Compass, you should set the Pointer/Arrow to the above (San Jose degrees), on the Right side of North. This will provide you with a “minus” reading, when reading the Compass.
You should then set the outer ring on the Compass, where the 180° mark is aligned with the linear axis/line of the Compass frame. Then when placing the Cursor in the center of the “Arrow” (North), it will “mechanically” point you to the True Azimuth of North.
Then you can look straight from South end of the Compass toward North, having the Dish in front of you, and move the Motor/Dish assembly left or right, setting it where the center of your LNB, and the center point of your Dish, are in direct line with the axis/line of the Compass. Then just lock your Motor down on the Pedestal. Assuming you have the Motor Shaft “centered”, and the Dish centered and tightened on it. At this time, the LNB should be vertically aligned and tightened with no “tilt/skew”. The Arc of the Motor Shaft, will compensate for the skew needed, at any given point, when you have the Latitude Elevation set correctly for the Motor.
This should set the “peak/True South” of the Arc of your Motor Shaft, in the right place. Then of course, “electrically” move the motor over to the Azimuth of your nearest Sat, and set the Elevation. I’m sure there may be minor adjustments to both that will be necessary, when getting the Strength and Quality of the Sats at the limits of your FOV. Hopefully you’ve adjusted the Motor Pedestal to be Plumb.
And IF you’re interested, take a look at
http://www.satelliteguys.us/showthread.php?p=592999#post592999 Post #6, where you’ll see/click on attachment, of an adjustable Pedestal Motor Mount, which may give you an idea for yours. I do have a more detailed drawing, if you’re interested. (Jack Bolts are more detailed)
I felt compelled in going into detail in the procedure, and I do NOT presume ignorance on your part! Lots of people read these Posts, and this detail may help someone else, later. Hopefully, clear instructions on setting True South, and the other necessary adjustments, will be included with your new Motor.
All you probably wanted, was just a conformation about your Magnetic Declination.
I admit, I’m gabby, and over think things, according to Iceberg anyway!
