GSS PTIS, Руководство по сборке, Страница: 22 / 36

- 22 - - 22 -
Setting the hierarchical modulation
In order to attain with less field strength a greater range for
broadcasters, with DVB-T so-called “hierarchical modulation”
is used. In this process, several data streams are modulated
onto a DVB-T data stream using “Quadrature Amplitude
Modulation” (QAM). The robust “High Priority” data stream
(HP) with a lower data rate is modulated onto the more sen-
sitive “Low Priority” data stream, which possesses a higher
data rate. In good reception conditions, the receivers can
receive both data streams; in poorer reception conditions,
only the “HP” portion.
• By pressing set to “ high “ or “ low “
—> not relevant in the case of standard modulation.
• Press the button.
—> The “Selecting the input transport stream” – “ INPUT ”
menu is activated when the input signal source “ Tun-
er A ” without a CA module installed and “ Tuner B ”
are programmed (page 20).
Programming the input signal source “
Tuner A
” with
a CA module installed the “Setting the operating volt-
age for the CA module” – “
CA Supply
” menu is
activated (page 31).
• Set channel strip “ Tuner B ” in the same way as channel
strip “ Tuner A ”.
Tuner A /
Tuner B /
ASI
Bx 4A
C30 (546.0)
INPUT
OK
Å Ï
/
Å
Bx 4
Tuner A OK
INPUT
=>
C
D
Kanalzug “Tuner A” mit CA-Modul
Channel strip “Tuner A“ with
CA module
Kanalzug “Tuner A” ohne CA-Modul,
Kanalzug “Tuner B” /
Channel strip “Tuner A“ without CA
module,
Channel strip “Tuner B“
Frequenz / Feinabstim
Frequency / Fine tunin
C5…C12, C21…C69
-64…+64
/
Tuner A
Tuner B
Bx 4A
Priority: high
INPUT
high / low
Tuner A /
Tuner B /
ASI
Bx 4A
C30 (546.0)
INPUT
OK
Å Ï
/
Å
Bx 4
Tuner A OK
INPUT
=>
D
C5…C12, C21…C69
-64…+64
Tuner A
Tuner B