Learn how to install and align an offset satellite dish by yourself without using a compass or satfinder.
Where are the satellites
If you answered "on the geostationary orbit" you are right (note that we are talking here only about satellite TV and not other services that use different types of satellites). Now let's imagine that this orbit is a circle that you can see. How it would look as you would see it from your current position? If you look straight to north or south this is what it looks like.How do you "see" the satellites |
- The closer you go to the equator, the more you'll see of the "edges" of the orbit. It just gets higher and higher to the point of being vertically straight above you at equator.
- The satellite that is on the same longitude as your current location is on the "top" of the orbit and it is the highest and most distant one. All vertical polarised signals coming from this one are vertical on earth too.
- You see the other satellites that are not on the same longitude with you rotated.
Let's see what we got from this.
1. LNB skew
You should know that when you place the LNB in its holder you rotate it according to the satellite position. Why? Because you "see" the satellite rotated on the orbit if it is not on the same longitude with you.
The best thing is that you don't even have to skew the LNB. You could rotate the antenna. But how would you mount it now? Ain't it very easy to rotate the LNB instead of the antenna?
If you want to keep the LNB straight, rotate the dish |
But what is the value of the skew? The exact value can be calculated using dishpointer.com. The LNB skew is the least important parameter of your dish setup. It affects the quality of the signal but you still get something as long as your deviation is no more than 10 - 15 degrees from the correct value (as a side note, if you would rotate the LNB at 90 degrees multiples you would have to invert polarities in your receiver).
If you would be using a H-H motor, the motor will rotate the dish like you see in the above image, thus no LNB skew is required for H-H motorized offset dishes.
2. Elevation
Elevation is the parameter that affects the vertical angle of your dish. The closer you get to the equator it increases (it is 90 degrees at equator for a satellite that is on the same longitude with you). It also increase the closer you get to the satellite that is on the same longitude with you (this is the "highest" satellite on the orbit from your location).
This is a critical parameter. Do your best in trying to set it using the markers on the antenna mount. If you got it right, you're almost done.
3. Receiver
Before mounting the antenna on its pole, connect the LNB to the receiver. Turn on the receiver and look on no matter what satellite or frequency at the signal level. With a working LNB, a good receiver will always show some signal level and zero quality.
You don't need a satfinder (they only show signal level, it doesn't matter where it came from or what kind of signal is). We are only interested in signal level to see if the LNB is working, otherwise quality matters. This is what we want to get.
The next thing is to select the satellite you want to receive from the menu and choose a working transponder. This is very important because if you don't set your receiver to a frequency that carries the correct signal or no signal at all, you'll be wasting time pointing a dish that will never work.
There are plenty of satellite list sites, but I recommend:
- satellite company own lists. For example, in Europe, Eutelsat offers its own channel list.
- television sites that publish such kind of information.
- third party lists, like en.kingofsat.net are good if you look for an important television without any recent changes.
It is also very important that your receiver can handle the signal that is transmitted. Do not attempt to receive DVB-S2 with a DVB-S receiver. Avoid also PLS or other modulations than QPSK and 8PSK.
Receivers display signal quality in more than one menu. It is important to display it in the antenna setup menu, where it is updated more frequently and some receivers also have a sound indicator.
And at last, you must assure you can receive the desired satellite from your location. Satellite coverage maps are available online on satellite companies pages or on SatBeams Footprints. You will also find there an estimate of the dish size. Remember that always, bigger is better.
And at last, you must assure you can receive the desired satellite from your location. Satellite coverage maps are available online on satellite companies pages or on SatBeams Footprints. You will also find there an estimate of the dish size. Remember that always, bigger is better.
4. Azimuth
This represents the horizontal rotation of the antenna (left - right). You don't need compass for this one. Mount the antenna on the pole and slightly move it to the left or to the right. Slightly with no sudden moves. Some receivers have a delay time before they actually demodulate the signal and calculate the quality. If you are in a hurry you'll miss the signal.
Patience is the most important here. If you fail to get any signal and you are sure that everything is set up correctly, start tweaking the elevation. Cheap antennas have very bad elevation markers and it can become a hassle to get it right. Lower the elevation a bit, tighten the screws, then try again to move left-right. Failed once again? Set the elevation a little higher than it was initially and repeat the move.
Got the wrong satellite? Sometimes, you get signal on a transponder, but when you scan it there are completely other services than what you expected. You're on the wrong satellite but at least you managed to find one. If you could identify it by the name of the services that are broadcasting there it would be great.
Once you received one, the others are easier to find. You will know how to adjust elevation. If you're on a higher satellite than you wanted it's clear that you should lower the antenna.
After you got signal quality try to adjust azimuth for the highest quality level. Then tighten the screws because you're done with azimuth. Now you can try to improve the quality by readjusting the elevation and the LNB skew.
Good luck!
Coverage maps:
Resources
Here are some useful websites and Android applications.Coverage maps:
Services lists:
Android tools:
Have you ever pointed a satellite dish by yourself? What difficulties have you experienced?
is there an article on the installation of the IS20 dstv model?
ReplyDeleteThank you so much. Now I can align manually.
ReplyDelete