Oki OKIFAX 5400 Maintenance Manual page 331

TELU/TEL-W2/TEL-W1/TEL-W2D/TEL-W2F
7)
8)
9)
40838301TH Rev.1
Return Loss
The return loss setting is performed by SW2-2 to 6. One of the bits is set to ON for each
individual country. When SW2-3 is set to ON, the impedance is set to 600 W's series.
AGC (automatic gain control)
AGC is function for adjusting the sending and receiving levels automatically in
accordance with the line current values, so that the optimal communication level is
automatically set. The circuit section to determine the AGC characteristic is formed by
the group of resistors R41, R43 and R44 connected to the AGC terminal of the speech
IC. The AGC gain is high wen the resistor values are small, and the AGC gain is low
when the resistor values are large. The AGC gain is adjusted by ON/OFF setting of
SW6-2 and 3 connected to R43 and R44.
Manual Pad
The manual pad is used for a countermeasure by the ON setting of SW6-1 when
howling has occurred because of line conditions. (normally set to OFF)
Note: Adjustment Sequence of Characteristics
Since individual characteristics are interrelated to each other, the settings shall
be performed in the following sequence:
(1) DC resistance
(2) Return loss
(3) Sending level
(4) Receiving level
(5) Side tone level
A3 - 50