http://www.satcure.co.uk/tech/lnb.htm
"Quad-output" or "Quad universal" LNB
This can feed four separate receivers. Each receiver has independent control of polarisation and band via 13/17v switching and 22kHz o/off respectively. This LNB is used with the new Sky Digiboxes that have two LNB inputs and internal Hard Drives for recording a programme while you watch another. Two LNB outputs go to this "Sky Plus" Digibox and the other two LNB outputs can go either to two standard Digiboxes or to one other "Sky Plus" Digibox.
"Quattro universal LNB"
This has four fixed outputs and is used only in "head end" I.F. distribution systems for apartment blocks. One LNB supplies a head end unit that can provide (typically) up to 16 outputs for separate Digiboxes. The four outputs of the LNB are as follows:-
1. Horizontal polarisation low band
2. Horizontal polarisation high band
3. Vertical polarisation low band
4. Vertical polarisation high band
Y
ou should not connect any of the outputs, 1 - 4, directly to a receiver unless you want to restrict viewing to just one of the four options. Even if you do, the receiver may not work. It's not a good idea.
Use the Quad instead.