they all have to be locked on to the same satellite, like the astra , or hot bird , ect , unless you have a very large dish, or use the dish you have 80cm, and get a Lnb quattro , look it up " maplins or stores . like them , then you can get 3 cables , and run them from the new L n b thats on the end of your dish , to the 3 recievers , but dont take down the dish or try not move it out of line when doing ths, you might get away the dish size your useing, if your in the uk , for the fta channells,
mick, November 2008