In order to see to that two complete sets channels at the same time can become broadcast via a satellite system, become the signals signals signals on the moment of transmissie linear polarized: vertical and horizontal. For optimal reception serves the reception probe of the LNB precise in line to stand with the polarization of the coming in signal.
Only when the LNB precise in line not stands with the desired polarization, will optimal signal strength become realized (cross polarization) and will program signals with other polarization be visibly.

The LNB is the simplest off to put with a selective signal strength meter, that has been geared to a channel of the unwanted polarization.

The complete LNB must then become twisted that the signal with the unwanted polarization minimally is, or whole disappeared.

Through it apply of QPSK- rnodulatie on digital signals becomes the transmit power over the entire width of the transponder spread. The digital signal is thus not - as by FM-modulated analogous signals - around the in the middle of concentrate (see image). Between the adjoining FM-modulated analogous carrierwaves can become the unwanted polarization visible. By turning at the LNB and through the unwanted draaggolf till a minimum back to bring, can the cross polarization good become turned away.

Between adjoining QPSK-modulated digital carrier waves exists too little space. It is about that advisable that the FM-modulated has to check the carrier waves there over he finished yards of the LNB.

Through the deviant manner on which the QPSK-modulatie the dispatched are in a position to over the tie width of the transponder spreads, arises an overlapping of the frequencies (see illustrations 1 and 2). Through that are digital broadcasts sensitive for a not-optimal positionering of the LNB.