Selecting a vendor:
Look for a company with more than just consumer back-yard installation experience.
Call other radio stations, TV stations and cable TV systems for recommendations. Radio satellite experience is more valuable than TV experience.
Look for a vendor that has experience installing dishes in the 3 to 5 meter range.
Ensuring correct assembly:
Maintain the parabolic shape. Follow the assembly instructions carefully. Once the dish is assembled, look across the face of the dish along two diameters about 90 degrees apart. The near and far edges should be in a single plane.
Set the focal length. Which is the distance from the feed element to the center of the main reflector. Sometimes it's called "F:D", for focal-length-to-diameter ratio. Some dishes have fixed length rods to prevent the focal length from being set incorrectly. For those dishes with adjustable focal lengths, the manual may tell you to adjust it to a specific measurement. You should treat this number as a starting point and not the final adjustment. After the antenna is assembled and pointed, you should adjust the focal length for the maximum desired signal or minimum undesired signal, or both.
Prevent antenna icing. Both snow and freezing rain can distort an antenna's pattern allowing increased adjacent satellite interference as well as reducing the desired signal. Heaters can be used to keep snow and ice from sticking to the dish. Heaters are very expensive ($1,500 to $3,000) and need to be turned on by an operator or an automatic device. The cost of powering the heaters also needs to be taken into consideration. Antenna covers are another option that places a vinyl or treated fabric cover over the front of the satellite dish. Antenna covers are a medium priced solution (about $1,000). Hydrophobic coatings, which can be painted or sprayed on the dish, make the dish slippery so that snow and water slide off the dish. It costs about $300 per application and lasts about two years. Snow can also be removed the old fashioned way - with a broom or a shovel. However, caution should be exercised to not dent the dish and ruin the true parabola.