Elevation&declination,whats the difference?

jonjamhill

Hi I'm a newbie to the forum. I need to know what is the difference between elevation and declination angle when setting a satellite dish. The reason I ask is I have just fitted a motorised dish (everything is working ok),but when I have come to the last bit in the installation manual it goes on about setting the declination angle on the dish.Now I do not know what this means.I have set the latitude/elevation on the motor accordingly but how do I set the declination angle on the dish ,all that is on the dish bracket is a scale from 0 to 30 ,the manual I got with the motor tells me that my dish angle bracket should be set at 22.2 and the declination angle set at 7.8 (according to my location). I have set the dish bracket angle at 22.2 ,but how do I set the 7.8 without moving the angle of the dish from 22.2 .Do I deduct the 7.8 from the 22.2 and set the dish at 14.4 or do I go the other way and add the 7.8 to 22.2. It's very confusing to me this and I do apologise for my ignorance, but I do hope someone can explain it more clearly.

HB13DISH

Try to search the forum by typing:

elevation and declination angle

You will be surprised how much information you will get.

stocksie

The geostationary orbit for satellites is straight out from the equator of the
earth. If we were setting up a dish living on the equator the elevation angle
would be 90 degrees and no declination. Our latitude would be 0 degrees of
course. Because we are about half way up the earth curvature (equator to north pole at about 55N in your case) then the elevation setting will be 90 minus 55 = 35. Because we now will be looking straight out from 55N to infinity distance we will, in theory, miss the satellite belt by our distance from the equator. The satellites are 35Km distance out (not infinity) we therefore need to "nod" the dish by approx 6-10 degrees and
this is the declination angle. The two angles should be juggled with to
get the dish to trace the same arc as the satellites appear. Too "peaky=
too much declination. Too flat = increase declination. When carrying out this declination angle adjustment an equal and opposite angle adjustment is needed to the elevation setting. Most motors have two scales on either
side calibrated in elevation and latitude degrees. 45 = 45!