Satellite TV Reception Basics

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Satellite Dish Installation Guide for a C Band Dish (Continued)

The Actuator Arm (The Dish Mover)

Rear view of a typical Linear Actuator Arm. This arm is set up for Linear East / West Use Satellite Dish Actuator Arm

Now that we have the proper LNB mounted on the feedhorn, the feedhorn mounted on the dish and centered exactly, and the dish mounted on a plumb and properly secured pole, we are ready to connect the actuator arm. Make sure you use an actuator that is properly rated for the dish it is attached to. You should never use an 18" actuator arm to try and move a solid 12-foot dish! It may work for a while but the chances are good that you will be replacing it in short order. Try to get the best heavy-duty actuator arm you can - it will pay for itself many times over in years of trouble free service.

Aligning The Dish

Now we come to the hardest part of the installation. If you pay close attention to the following procedures it will pay off in the long run with better reception on weaker C-Band satellites.

Three adjustments are required to ensure proper tracking of the arc: Azimuth (east/west heading), declination offset angle and polar axis angle (inclination angle). These parameters should be set while the dish is aimed toward its highest position, namely towards the Northern most satellite.

Setting the Polar Axis Angle - The polar axis angle is set by placing an inclinometer on the polar bar and then raising or lowering the dish to that angle. Setting the Satellite Polar Axis Angle

The azimuth must be set right in order to detect all the satellites in the viewable arc. Most dishes have a flat plate on the mount that can be used as a sighting reference. A hand-held compass is the most effective type for lining up the mount. Remember that a correction for magnetic variation is necessary. Add magnetic variation to the compass heading for west magnetic variation; subtract for east.

The polar axis angle or inclination angle is within fractions of the site latitude. Most mounts have one or two long threaded rods that are used to adjust the polar axis angle. An inclinometer resting on the axis bar or back part of the mount is used to set this angle.

The declination offset adjustment lowers the sight of a dish to the arc of the satellites. Declination is greater in locations farther away from the equator. Just like the offset angle, it is measured with an inclinometer. The difference between the two readings, one on the main bar, and one on a flat spot on the back of the dish, should be equal to the declination offset.

The easiest way to set the declination offset is with an inclinometer placed on the back surface that is parallel with the face of the dish. Or via a flat board placed in a vertical direction spanning the rims. This reading should be equal to the sum of the polar axis and declination angles.

	Setting the Declination Angle - The declination angle is set by placing an inclinometer on a flat service of the dish that is parallel to the line between the rims and adjusting the declination bolts until the reading equals the sum of the polar axis and destination angles.
Using the Dish Face to Set A Declination Angle - If a flat surface cannot be found on the rear of the dish or on the hardware that supports the declination adjustment, the declination angle can be set by placing an inclinometer on a flat board that rests on the face of the dish.

Determine the latitude & Longitude of your installation by using our program.

When the declination is properly set, the procedure is to set the dish to true North (not magnetic North. You need to compensate and use the polar axis adjustment to capture the northernmost satellite visible from your location. This is called the zenith satellite. Once you are peaked at the northernmost satellite you can use the actuator control on your receiver to move the dish to the lowest satellite off the horizon you can see. This is called the extreme satellite.

Once you have located the extreme satellite, gently push up and down on the edge of the dish to see which direction helps clear up the picture. If pushing down on the lip of the dish clears up the picture, then you need to rotate the polar mount counter clockwise. If pushing up on the lip of the dish clears up the picture, then you need to rotate the polar mount clockwise on the pole.

After you have made the azimuth adjustment, return the dish to the northern most satellite and use the elevation adjustment to clear the picture up. Keep moving back and forth between the extreme satellite and the zenith satellite using the polar adjustment and the elevation adjustment respectively until the dish tracks the arc.

You are now ready to run your cabling as in the KU setup and install the decoder and start viewing!

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