In an SMATV installation, how might it be possible to see television programmes from the different polarities of a satellite?
If an individual QPSK receiver is being used and if the distribution is prepared for it, one option could be to use IF processors: UC-202/212. If television programmes are required in PAL BG, the TP-551 modules can be used.

What purpose does the DiSEqC protocol serve?
This protocol is used by individual QPSK receivers to receive the signals from two satellites (8 polarities) in installations with multiswitches.

Using a ZF-701, I am unable to obtain a level of 120dBµV from its output, since at this level the BER deteriorates considerably.
We are working with a broadband amplifier, for which reason the output level given in the catalogue is for 2 carriers. For 30 transponders (one polarity) entering the amplifier, we would have to reduce the level to 109 dBµV.

When is universal LNB used and when Quad LNB?
The universal LNB with switchable output is used in individual installations. On the other hand, the Quad LNB, with four outputs, is used in MATV installations.

What minimum level must there be at the outlet for an individual receiver to work?
For QPSK, from 47 to 77 dBµV, for QAM from 45 to 70 dBµV , and for analogic satellite from 47 to 77 dBµV.