- 8 -
CGT 660
e
ffeCtive
assignment
of
Cable
Channels
with
low
bandwidths
s
eleC
p
lex®
Channels with low bandwidths are the result of filtering out several
unwanted stations from the data stream. These "narrow" channels can
then be arranged in one channel to save space.
—> The required bandwidth (in kHz) is roughly equal to the symbol rate
(kSymb/s) plus 20%.
The modulator in this module employs automatic neighbouring-channel as-
signment. This means that when the output channel or the output frequency for
channel strip "
A
" is set, the output channel or the output frequency of channel
strip "
B
" will always be 8 MHz above the output channel or the output fre-
quency of channel strip "
A
".
If SelecPlex
®
will be used, the normal channel separation of 8 MHz can be
reduced up to 2 MHz via the frequency setting for channel strip "
B
".
3
i
nstallation
– Ensure the head-end station is mounted so it will not be able to vibrate.
Avoid, for example, mounting the head-end station onto a lift shaft or any
other wall or floor construction that vibrates in a similar way.
– Before installing or changing a module, switch off the head-end station or
unplug the power cable from the mains power socket.
Take measures to protect against ESD!
•
Open the housing of the head-end station in accordance with the assembly
instructions for the CSE 2800.