4x1 DiSEqC Switch The DiSEqC switch will enable the user to select one LNB signal between 4 different LNBs of any type. The 4 input ports marked LNB1, LNB2, LNB3 or LNB4 are connected to the 4 LNBs, which may be on 4 different dishes, and the output marked RX is connected to the receiver. The selection of the LNBs is done by choosing the appropriate Tone Burst A, B, C, or D in the menu of the receiver.