Questions about my first motorized dish install

[Rob Relf]

I am getting started in the FTA world and have some questions about the dish install since I have never done a motorized dish. I just received my 3ABN 90cm dish and it seems like very good quality. The dish mounting bracked is stamped Azure Shine and I particularly like the fact that the LNB mount is located by 3 arms bolted to the rim of the dish. It seems the LNB can never be out of alignment in relation to the dish itself. I have also received a Stab HH90 motor and an Invacom QPH-031 LNB. I'm waiting to order a Genpix SkyWalker-1 USB box if it ever comes back in stock!

I'm at about 48 degrees latitude and -122 degrees longitude and for my setup I got data from DishPointer.com - Satellite Dish Pointer / Alignment Calculator with Google Maps of: Motor Latitude Angle matching my actual latitude; True Azimuth of 180 degrees; Magnetic Azimuth of 162.1 degrees; Dish Elevation of 38 degrees and the one that is bugging me, Declination Angle of 7.1 degrees. Stab's installation instructions make no mention of this angle and I can't seem to relate it plus or minus to any of the other numbers I have. I did some Googling but haven't found a satisfying answer. I am also thinking that this number is extraneous for me and already figured in to the motor and dish angles taken together. Even if I don't need to include it in my calculations, I am the sort that has a hard time accepting things without an understanding of the underlying facts or reasons. Anyone care to tackle an explanation?

I see there are degrees marked on the clamp for the neck of the LNB for adjusting LNB skew. Am I correct that with a motorized dish at the midpoint of motor travel that will be set up pointing true South that the LNB should be skewed at zero and after that the skewing is automatically correct as the dish tilts and rotates?

Rob

 

[mastermesh]

if you set up the motorized correctly you should not have to mess with skew since it'll do it for you... You may however have to tweak a little bit if you're just barely off of true south, have a pole that isn't 100% plumb, or somehow managed to be a tad off center on your true south. Typically though, once you get true south in, and find you can get good quality on both sides of the arc you are good to go. Just make sure that your quality is as good as you can get it elevation wise... which may require adjusting by hand without even touching a bolt. a fraction of an inch can make or break you, especially on very low signal feeds and things.

 

[concord]

You use the "Declination Angle" by subtracting/adding it to the dish elevation angle, for the HH90, check out:

How to install an HH-Mount Motor? Applies to DG240-SM3D22-STABHH100-HH120-Motech-SG2100

 

[Rob Relf]

Thanks for the replies. The Sadoun help page in the link provided is powered by the same dishpointer site that I already used. I have done some more reading online and have found the answer I was seeking: the declination angle is subtracted from a fixed number (the bend angle of the dish mount arm coming off of your motor) to arrive at the dish elevation number. In the case of the Stab HH90, this is 45 degrees (and is different for different motors). This is why I couldn't correspond the declination angle to any of the numbers I already had in front of me. The dish elevation angle given on the website already takes it into account so I think it is actually confusing rather than helpful since no explanation of its significance is provided there.

Rob

 

[concord]

Glad you were able to figure it out....when I set mine up, I think he had a different page than the current one...