Initialization Phase 3 - Dvb-T; Configuration Of The Modulator - axing SKM 40-00M Betriebsanleitung

Operation instructions | SKM 40-00M | SKM 40-04M | SKM 80-00M
3.6. Initialization phase 3 – DVB-T
Note: Depending on the installed firmware the signals are modulated into DVB-C or DVB-T (see 3.5 on page
26 and 3.7.1 on page 31).
In phase 3, the modulators are configured.
After assigning programmes to the modulator the fill level has to be conntrolled. With the parameters of the
modulator, the datarate can in certain circumstances be reduced.
3.6.1.

Configuration of the modulator

Norm:
Output channel:
DVB-T modulation:
28
In this selection field, you can set the norm for the output channel spacing in
the output channel window.
The first modulator can be set to any output channel between S2 and CH 69.
The other three modulators are automatically set by incrementing the output
channels in accordance with the chosen channel spacing.
For example: modulator 1
modulators 2, 3 and 4
The modulation can be set on QPSK, on QAM 16 or on QAM 64.
The QPSK-setting provides the smallest data rate to the output channel. The
QPSK-modulation process is used in bad distribution networks because of its
robustness against disturbances and of its safe transmission.
The QAM-modulation process allow reaching higher data rates, so that more
programmes can be transmitted on a channel. The QAM 64-modulation gives
the highest data rate.
•
QPSK (2 bit) – small data rate – very robust signal.
•
QAM 16 (4 bit) - middle data rate.
•
QAM 64 (6 bit) - high data rate.
2020-02-23 | Technical improvements, changes in design, printing- and other errors expected.
= Channel 21
= Channels 22, 23 and 24