RFL 9780 RFL Electronics Inc.
April 8, 2003 13-7 (973) 334-3100
13.4.1 METER SELECT
The module can provide a signal to an external meter. The external meter output can be configured for
either a current meter or a voltage meter.
With jumper J1 in the “A” position, the range of the external meter should be from +1 to -1 Vdc. This
would correspond to a full-scale range of ± 10 dB, with 0 V indicating 0 dB.
With jumper J1 in the “B” position, the range of the external meter should be from 0 to -100µA. This
would correspond to a full-scale range of ± 10 dB, with -50µA indicating 0 dB.
With jumper J1 in the “C” position, the range of the external meter should be from 0 to –5 Vdc. This
would correspond to a full-scale range of ± 10 dB, with –2.5 Vdc indicating 0 dB.
13.4.2 METER NULL
R30 is used to null the meter to read 0 dB. This is typically performed with the system installed and the
far-end station transmitting a guard signal. Note that a dramatic change in receive level may indicate a
problem with the line. Following significant changes (for example, modifications to the line) the system
start-up procedure must be performed.
13.4.3 ALARM LEVEL
R58 is used to set the low-level alarm threshold at the desired level. This is normally performed by
attenuating a normal receive level to the desired threshold amplitude and adjusting R58 to activate the
alarm.
13.4.4. GUARD LEVEL
The position of J2 is related to the desired trip boost level in accordance with the table below.
Trip Boost J2 Position Example
None 10W Display will read 0dB when receiving a 10W level in a 10W/10W system.
3.33:1 3W Display will read 0dB when receiving a 3W level in a 3W/10W system.
10:1 1W Display will read 0dB when receiving a 1W level in a 1W/10W system.
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