User's Guide

DANIELS
ELECTRONICS LTD
TM
CI-PM-3 Paging Modulator Instruction Manual 3-3
4. Monitor the Communications Test Set and adjust FREQ ADJ potentiometer R82 for the
transmitter operating frequency +/-1 Hz.
5. Set the transmitter front panel NORM/KEY TX switch to NORM and replace JU6-A.
3.7 Reference (Analog Paging) Adjustment
CI-PM-3 Reference frequency adjustment is factory set. It is strongly recommended that they not
be altered. The following procedure applies only if field adjustment is required.
1. Ensure shunt jumper JU6-A is installed.
2. Set shunt jumpers JU23-A and JU41-A (or not installed).
3. Set the transmitter front panel NORM/KEY TX switch to KEY TX.
4. Monitor the Communications Test Set and adjust REF ADJ potentiometer R24 for the
transmitter operating frequency +/-1 Hz.
5. Set the transmitter front panel NORM/KEY TX switch to NORM.
3.8 Test Data Symmetry Adjustment
1. Set the oscilloscope for 1.0 V/Div (vertical) and 0.5 ms/Div (horizontal). Monitor TP10.
2. Set shunt jumpers JU23-A and JU41-B, and set JU36 to bypass.
3. Set SW3 (SET MOD) to 2 LEVEL and SW4 (SET DEV) to the center or “Continuous Bit
Stream” position.
4. Adjust R70 (Test Data Symmetry Adjust) for symmetrical positive and negative pulses (i.e. of
equal width) as measured at TP10.
3.9 2 And 4 Level Deviation Adjustment
1. Set shunt jumpers JU23-A and JU41-A (or not installed).
2. Monitor TP11 with a voltmeter and adjust R110 for approximately 4 volts at TP11.
3. Monitor the transmitter frequency and deviation on the Communications Test Set and set the
transmitter front panel NORM/KEY TX switch to KEY TX.
4. Set shunt jumpers JU23-A and JU41-B.