Line of sight
Which way do I point a satellite dish?
Short answer
Look up the azimuth, elevation and skew for your postcode and your satellite, set the azimuth as a true bearing, then fine-tune on signal strength.
Every television satellite you are likely to want sits in the geostationary belt, directly above the equator at a fixed longitude. That makes it a stationary target, which is why a dish can be bolted to a wall and left alone.
It also makes it a small target. A dish has a beamwidth of roughly one to two degrees, so this is the one job on this site where a phone compass is a starting point rather than an answer.
Method
Step by step
In this order. Each step assumes the one before it is done.
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01
Get the three numbers
Azimuth is the compass direction, elevation is the angle above the horizon, and skew, or LNB rotation, corrects for the fact that you are not on the equator. All three depend on your exact position and on which satellite you want. Every provider publishes a lookup for its own birds.
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02
Confirm whether the azimuth is true or magnetic
Almost every published dish azimuth is a true bearing. If you are setting it with a phone compass, select True north so the declination is applied. If you are using a physical compass, either add your local declination or find a source that publishes magnetic azimuths, and never assume.
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03
Check the line of sight before you drill
Stand at the mounting point, face the azimuth, and look up at the elevation angle. A tree, a chimney or a neighbouring roof in that line is fatal: these frequencies do not go through obstructions, and a tree that is thin in February will not be in July.
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04
Set elevation and skew, then tune on signal
Set elevation and skew on the bracket scales first, because both are easier to set accurately by measurement than by trial. Then sweep the azimuth slowly with a signal meter or the receiver's signal screen. Move in very small increments and wait a second or two: the on-screen meter lags, and most failed installs are someone sweeping past the peak too fast.
How wrong can this be?
Accuracy
A phone compass gets you within a few degrees, and a dish needs better than one. Treat the compass bearing as the direction to stand and look, then let the signal meter make the final call.
Related
Other guides
The basic one
Which way is north?
If you are on a phone, press Start compass and turn until the bearing reads 000. If you are not, and the sun is up, stand with the sun on your right in the morning and you are facing roughly north.
No instrument
Without a compass
Put a stick upright in the ground, mark the tip of its shadow, wait fifteen minutes and mark it again. The line from the first mark to the second points roughly east.
Fixed installation
Aim a solar panel
In the northern hemisphere, face a fixed array due true south, 180 degrees. In the southern hemisphere, due true north, 000. Tilt it at roughly your latitude.