Oki B 4100 Maintenance Manual page 485

7) Return Loss
The circuit section which determines the return loss is formed by R26, R29 and C21.
8) AGC (automatic gain control)
The gain of the AGC is determined by the resistor value of R41. To lower the AGC gain,
raise the resistor value of R41. To raise the gain, decrease the resistor value.
9) Charge Pulse Elimination Characteristics
The Germany network sends 16kHz pulses for charging to the terminal while the terminal
is connected to the line. The terminal should not cause any mulfunction for the communi-
cation by the charge pulses. In TEL-W2D PCB a parallel oscillation filter is formed by L3,
C305/L2 and C301 which eliminates the charge pulses.
10) Manual Pad
The sending/receiving levels are lowered by 6dB when SW6-1 is set to ON. Use the
setting as a countermeasure when howling is generated because of line conditions (nor-
mally set to OFF).
40055101TH Rev.4
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