]]More Dishes, More Satellites[[
For a greater choice of programming it is possible to 'look' at several satellites. This can be done by using a motorized dish or a combination of several fixed dishes and
LNB's.
To use multiple dishes a simple switching system called DiSEqC (Digital Satellite Equipment Control™ - developed by Eutelsat) is all that is needed, but the receiver must be DiSEqC compatable. The DiSEqC switch is usually fitted near the dishes and a single cable feeds to the Receiver. The Receiver box sends control signals along the cable to the DiSEqC switch to automatically select the correct combination of dish/
LNB and satellite.
Upgraded versions of the DiSEqC protocol allow for control of motorised dishes (DiSEqC 1.2 and 2.0).
A different type of motorized system is the horizon-to-horizon (H-H) method. Here an electrically operated screw-jack pushes and pulls the dish which pivots on a special mounting bracket. This makes the dish accurately follow the position of the satellites along the Clark Belt. Receivers incorporating this type of motor drive will usually have 'Positioner' included in the name/description.
For even greater flexibility
LNB's are available with single, dual, quad or octo (8) outputs. Each output is totally independent from the others. This allows multiple receivers (living room, bedroom, kitchen, etc) to connect to a single dish/
LNB.
If 'looking' at two closely spaced satellites (eg Hotbird [13°E] and Astra-1 [19E°]) it is possible to use one dish and two
LNB's mounted on a special extension arm. The dish and one
LNB is focussed on the weaker of the two satellites. The second
LNB is moved along the extension arm until a satisfactory signal from the second, stronger satellite is received (this picture shows a single output
LNB 'looking' at Hotbird and a quad output
LNB 'looking' at Astra-1 - note that one output from the quad
LNB is not in use).