Dish Installation at 28° East

This is a satellite dish installation guide for the satellites used for reception of domestic British TV and radio services.
This guide is mainly for the Astra 2E and Astra 2F satellites, these carry the main PSB channels from the BBC, ITV, Channel 4 and Channel 5.
The other satellite used is Eutelsat 28A positioned at 28.5° east, they are so close together that only one dish and one LNB are required.

Those living overseas should note, that Astra 2E and Astra 2F have a UK spotbeam, this is used by the major terrestrial channels from the BBC, ITV Channel 4 and Channel 5.
Outside the intended area of reception (the British Isles), reception can be difficult and require large dishes.


Please see the reception reports maps for a guide to dish sizes at or near your location.

Astra 2 Reception Reports Map by Astra 2
Alignment Calculator for Sky Digital For both Sky and Freesat setup. This is for the UK only, type in your UK postcode.
Satellite Dish Alignment / Setup Calculator This can be used if you are outside the UK, has many other satellite positions.


Getting started

First, survey the site to ensure an unobstructed view in the direction of the satellites at 28° east, this is east of south. To receive signals, your satellite dish needs to be positioned correctly. When you have securely mounted your satellite dish, adjust your dish so that the dish mast is plumb, that is, exactly perpendicular to level – this is best achieved using a Spirit Level. With your dish now mounted and properly set, you are now ready to position your dish toward the satellites at 28.2° east. To set the dish you must first set the elevation, then set the azimuth.



Elevation

Elevation refers to the angle between the dish pointing direction, directly towards the satellite, and the local horizontal plane. It is the up-down angle.

First, loosen the nuts securing the two elevation bolts so that the dish easily moves up and down. Line up the elevation indicator with the tick mark corresponding to your elevation, then tighten the bolts. You may need to readjust the elevation up or down slightly to get the best signal.
Use an inclinometer, these typically have a bubble level and a rotary scale marked in degrees.
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Azimuth
Azimuth refers to the rotation of the whole antenna around a vertical axis. It is the side to side angle. Typically you loosen the main mount bracket and swing the whole dish all the way around in a 360 deg circle.
Set the azimuth by moving the dish left and right. Point the dish in the general direction of the satellite, By using a compass you can better pinpoint the direction with your azimuth number to correspond with the degrees on your compass.
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Finding the signal

Before switching on the receiver, make sure that the cable is connected correctly from the dishes LNB to the receiver. Connecting the cable(s) while the receiver is either on or in standby, could damage the receiver.
Always disconnect from the mains before tampering with the cable(s). You will need to access your receivers menu to view the Signal Strength and Signal Quality, non Sky and Freesat users should consult their user manual.

For Sky users

Sky users, go to SETTINGS, then SIGNAL.
If your dish is correctly aligned, there should be a reading for both Signal Strength and Signal Quality. Lock Indicator should read OK, Network ID should say something like 0002 and Transport Stream 07d4.
This is the signal of the ‘Default Transponder’, this is where Sky’s EPG is broadcast, along with the background music. If your receiver is not showing this information, then there is a problem either with your receiver, cable or dish. Check your connections and dish alignment.

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For Freesat users

If you are installing your Freesat receiver for the first time, you may have to go through the First Installation setup before gaining access to the receiver’s menu.
Freesat Users, go to Diagnostics. To access this option, press Menu on your remote, then choose System and then Diagnostics.
This is the transponder (frequency), of the most recently selected channel. Overseas users should first use a non Astra 2F frequency, then use one to optimise signal strength and quality.

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Fine Tuning

Once you have a satellite signal, it is important to fine tune the dish, to make sure you have the maximum possible signal strength. Loosen the elevation bolts, then gently continue turning the dish a little left or right (Azimuth).

Pause for a few seconds each time to allow the signal to stabilise. Once you have maximised the signal tighten the bolts. Then loosen the elevation bolts to further maximise the signal if required, the re-tighten.
One other important factor to mention is LNB Skew.



LNB Skew

lnbscewSkew refers to the angle of the LNB relative to the rest of the dish, you are maximising the gain of the LNB, his could be the difference between a good watchable picture or poor reception.
All geostationary satellites are located above the equator (the Clark Belt).
They are placed here to match the rotation of the earth. Inside a satellites footprint, LNB skew is not all that important, however as you approach the fringes of the signal footprint it becomes ever more crucial to getting good reception.
The LNB is kept in place by either a screw or a nut.

Loosen these and it will be possible to rotate the LNB left or right. The degree of tilt varies depending on your location.
Satellite appears to be tilted as viewed from Earth, this means the LNB has to be tilted to a similar angle so that it matches the geometry position of the satellite.

The degree of tilt varies depending on both your location and on which satellite you want to receive.
Skew varies from about 15º in the north of Scotland to around 22º in the south west of England, always rotate clockwise as viewed facing the front of the dish.

Most commercial satellite dishes have a certain amount of skew built in, the LNB will appear to be lopsided.
In areas where the signal is strong, skew is not such an issue, once outside the main reception area, skew becomes important
The LNB is locked in place by either a screw or a nut. Loosen it and the LNB will rotate in its housing. Rotate it one way or the other until the signal quality is maximised.



Effective Isotropic Radiated Power (EIRP)

Effective Isotropic Radiated Power (EIRP) is derived from the word isotropic which means equal in all directions. Effective Isotropic Radiated Power means, the power levels that would be received at any location if an antenna were radiating equally in all directions. Therefore, a 37 dBw EIRP reading means that a perfect antenna would direct 37 dBw or 5012 watts per square meter in all directions.

The reason that a transponder having rather limited power, typically in the 8 to 150 watts range, can apparently have such a high EIRP stems from the fact that this power is not radiated equally in all directions and is concentrated in a narrow beam (Spotbeam) aimed at the earth below.
Ku-band transponders having a total power of 50 watts have EIRPs as high as 48 or 49 dBw when this power is directed into a tightly focused spotbeam. EIRP levels refer to the power of signals measured at the satellite downlink antenna.

Official satellite reception maps (footprints), have very conservative values, this is good if you are inside the official reception area, as it is easy to determine the dish size required for reliable reception. However, satellites do not transmit in the way they are displayed on official footprints, so outside the intended reception area, it is mostly guess work.

 

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