Brother MFC990CW Service Manual page 470

Selector
No.
1
Cable equalizer
2
3
Reception level
4
5
| Modem attenuator
8
The modem should be adjusted according to the user's line conditions.
• Selectors 1 and 2: Cable equalizer
These selectors are used to improve the pass-band characteristics of analogue signals on a
line. (Attenuation in the high-band frequency is greater than in the low-band frequency.)
Set these selectors according to the distance from the telephone switchboard to the
machine.
• Selectors 3 and 4: Reception level
These selectors set the optimum receive signal level.
• Selectors 5 through 8: Modem attenuator
These selectors are used to adjust the transmitting level attenuation of the modem when the
reception level at the remote station is improper due to line loss. This function applies for
G3 protocol signals.
Setting two or more selectors to "1" produces addition of attenuation assigned to each
selector.
If selector 8 on WSW23 is set to "0," this setting is so limited that 10 dB (1 dB in France)
or higher setting only is effective. Note that in Japan and China, 9 dB or higher and 2 dB or
higher settings only are effective, respectively, regardless of whether selector 8 on WSW23
is set to "0."
WSW13
(Modem setting)
Function
App. 4-18
Setting and Specifications
No. 1 2
0 0 : 0 km
0 1 : 1.8 km
1 0 : 3.6 km
1 1 : 5.6 km
No. 3 4
0 0 : -43 dBm
0 1 : -47 dBm
1 0 : -49 dBm
1 1 : -51 dBm
0: 0 dB
0: 0 dB
0: 0 dB
0: 0 dB
1: 8 dB
1: 4 dB
1: 2 dB
1: 1 dB
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