ZETRON 4000 Series Installation Manual page 99

Jumper Switch Settings
Table 37: Jumper switch settings
Switch
JP1 Receive gain
JP2 Not installed
JP3 Source for Off Hook signal
JP4 Selects decode polarity for the external tone decoder
JP5 Selects proper de-emphasis network for receive audio A = Speaker audio *
JP6 Sets polarity for Off Hook input
JP7 Transmit gain setting
JP8 N/A
* Factory default setting.
Variable Resistors
Table 38: Variable resistors
Resistor
R1 *
R2
R3
R43 *
R46
R95
R96
R100 *
* Not used in normal operation of the phone coupler.
Description
Description
Sets the threshold for the internal carrier detector circuit.
Sets the receive level from the console. The range over
which this control acts is set by JP1.
Sets the transmit level to the console. The range over
which this control acts is set by JP7.
Sets the VOX circuit threshold.
Sets the threshold on the external COR input.
BAL R — used with BAL C to balance the hybrid
(match the coupler to the phone line).
BAL C — used with BAL R to balance the hybrid
(match the coupler to the phone line).
Sets the sensitivity of the Dial Click decoder circuit.
Series 4000 Phone Coupler (Optional)
Settings
A = LO *
B = HI
N/A
A = Internal
B = External *
A = Valid Low
B = Valid High *
B = Discriminator audio
A = High
B = Low *
A = HI *
B = LO
N/A
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