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HDMT 1290
Setting the output signal
In this menu, you can set the bandwidth, the carrier modulation and the spectral
position of the output signal.
Bx 4A
8MHz QAM64
COFDM-MODE
POS
Bandwidth of the output signal
To transmit the output signal in the channel range of C21 to C69 a bandwidth
of 8 MHz can be used. In the channel range of C5 to C12 a bandwidth of
≤
7 MHz must be set. Therefore observe the current output data rate (menu
“Stuffing”, page 25). If necessary change the COFDM settings or delete serv
-
ices by the station filter (page 18).
If frequency setting is selected you can set the bandwidth dependent on the
frequency of the adjacent channel.
Bx 4A
8MHz QAM64
COFDM-MODE
POS
•
Use
to set the bandwidth of the output signal (“
5 MHz
”
… “
8 MHz
”).
Carrier modulation
In this menu item the carrier modulation is set. At this the setting “
QPSK
” cor-
responds to the lowest and the setting “
QAM64
” to the highest output data
rate.
•
Use the
buttons to place the cursor under ”
QPSK / QAM…
”.
• Set the carrier modulation of the output signal using the
buttons
(“
QPSK
”,
“
QAM16
”,
“
QAM64
”).
Inverting the user signal
For exceptional cases and “older” digital cable receivers, the spectral position
of the user signal can be inverted “
NEG
”. The default setting is “
POS
”.
• Use
to place the cursor under “
POS
”.
• Use
to set the spectral position to “
NEG
”.
• Press the
button.
—> The “Setting the transmission parameters” – “
COFDM-MODE
” menu is
activated.