Level settings and adjustments, Line drive level, Transmit level – GAI-Tronics IDA1000A DC Remote Adapter Installation and Service Manual User Manual
Page 20: Dc threshold calibration, Balance adjustment

Installation
Model IDA 1000A DC Remote Adapter
01/05
16
Level Settings and Adjustments
Line Drive Level
Set the line drive level as follows:
1. With a service monitor connected to the receiver with maximum allowable system deviation, measure
the audio across P1-11 and P1-3.
2. Set jumper JU3 and switch SW1-3 for the level indicated. See the Jumper Position Table on page 15.
3. While measuring the input to the line J1-3 and J1-4 (on 4-wire installations, J1-2 and J1-5), adjust
Pot 1, the adapter
LINE DRV
level pot, for the desired level of drive, but no greater than the maximum
allowable.
Transmit Level
Setting the transmit level compensates for any losses in the audio control line. The transmit level is set as
follows:
1. Apply a 1000 Hz signal to the mic circuit of the remote desk set. This signal should be enough to
provide the desired reference level across the audio control line at the desk set end, normally
-10 dBm.
2. Adjust Pot 2, the adapter TX level pot, to obtain 2/3 system deviation from the base station
transmitter. If it is not possible to obtain the correct level near the center of the control’s travel, use
the opposite position for Gain Select, SW1-2.
DC Threshold Calibration
The dc threshold level is factory set and should not require adjustment unless field service is required. If
field service is necessary, complete the following steps:
1. Apply a –2.5 mA source to the control line.
2. Slowly adjust Pot 4, the calibration pot, to illuminate the
MON
LED.
3. Remove the –2.5 mA current. The
MON
LED should extinguish.
Balance Adjustment
The hybrid adjustment is factory-set and should not require adjustment. If field service is necessary,
complete the following steps:
1. Set switch SW1-8 up and SW1-1 down.
2. Adjust Pot 4 to full clockwise position.
3. Apply a 1000 Hz signal to P1-3/P1-11.
4. Measure the audio across P1-12/P1-4 and adjust Pot 3, the adapter
BAL
pot, to null (minimum).