Can I have more than one box?

November 28, 2008

Yes, of course you can

BUT

You will need to install a multi-output LNB on your dish (you’ve probably heard people talking about “quad LNBs”). The replacement of a single LNB with a multi-output one is straight swap.

Having installed the new LNB on your dish you then need to check the signal (See “how to fix your own dish”) then simply run cables from your new LNB to your boxes and your kids can watch Cbeebies while you watch the news.

Why can I only 1 box on an LNB? (a bit techi)

At it’s most basic level it’s because the LNB is not a simple areal it actually does some quite clever things.The digibox and LNB should be regarded as the reciever because they inter-react with one another

The signal from the satellite is polarised, that is to say it is transmitted in either a horizontal or a vertical plane, this means that 2 different programs can be transmitted on very close frequencies on horizontally and the other vertically, thus making very efficient use of the available frequencies. This is why the skew angle of the LNB is important when you are installing your dish

The LNB can be switched by the digibox to receive either horizontal or vertical transmissions, to achieve this the digibox sends 13volts to the LNB to receive vertical transmissions and 18volts for Horizontal

The signal from the satellite is in 2 frequency bands, 10.7-11.8Ghz(Lo band) and 11.6-12.6Ghz(Hi band) the LNB switches to Hi Band when it receives a 22Khz frequency signal from the digibox….

So if you if you do connect 2 boxes to on LNB and select a program that transmits on Hi band/vertical (22Khz/ 18volts from the box) on one, that is going to override any other selections on the other and in the worst case scenario if one box is trying to access a Hi Band/Horizontal channel(22Khz/13volts) and the other box is trying to access a LoBand/Vertical (0Khz/18volts) then neither box will get receive the correct signal

(Actually you can get multi-output LNBs which in effect have 2, 4, 8 or even 16 LNBs in one casing so you still have one box per individual LNB)

Written by Bart · Filed Under How-to