GSS HDM 660 T, Руководство по сборке

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- 12 - HDM 660 T
5 p
rogramming
5.1 p
repar ation
• Test the software versions of the head-end station and the COFDM module
and update them if necessary. The current software versions can be found
on the website "
www.gss.de ".
• Connect the test receiver to the modulator output on the COFDM module D or
to the HF output on the output collector if it is already connected (page 10).
• Adjust the test receiver to the output channel / output frequency of the chan -
nel strip to be set.
• Switch on the channel strip (modulator) if necessary (page 18). For each chan-
nel strip, there is an status LED which indicates if the channel strip is switched
on.
Status LED –
Channel strip ”A”
Status LED –
Channel strip ”B”
• Balance the output levels of the channel strips " A " and " B " and level them
to the output levels of the modulators of other modules used if the difference
in level is
≥ 1 dB (page 19).
5.2 n
otes on level set ting
In order to prevent interference within the head-end station and the cable sys-
tem, the output level of the COFDM module must be lowered by 8 dB com-
pared to modules with analogue modulators.