Incidentally, why does the LNB have to be at the dish-end?
The satellite dish has a parabolic shape ( more precisely it is a section of a parabolic dish, designed so that the LNB supporting hardware does not interfere with, or block the incoming signals ).
The dish collects the low level microwave signals broadcast from the satellite, and the shape of the dish reflects these to the focal point of the parabola. A "Feedhorn" - as shown above, is fitted at the focal point and directs the signals onto the LNB ( Low Noise Block ).
( The term LNB these days refers to one device which combines the feedhorn and LNB ).
The signal is then amplified within the LNB, converted to a lower frequency, and sent along the cable to the indoor receiver.
Remember - when considering your installation - if you are using Sky+ or a dual/twin receiver, you will need two feeds - one for the channel you are watching and one for the one you want to record.
If you have two Sky+ boxes running from one dish you will need a Quad LNB. ( 2 feeds per Sky+ box ). These are readily available from popular auction site(s) for around ten pounds.
