User's Manual

SECTION 2: FACTORY TEST PROCEDURE
401987 Page 13
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Receiver 2
Perform the following steps to adjust receiver 2:
Step 1 Inject an on-frequency carrier signal with an amplitude of -80 dBm, modulated with a 1 kHz
test tone at +/- 5.0 kHz deviation into Receiver 2's antenna port.
Step 2 While monitoring the voltage at RSSI2 Test Point with a DMM, adjust trimmer capacitor CV4
to midway between the points where the oscillation stops.
Step 3 While monitoring the DC level of the recovered modulation, adjust potentiometer R99 for a
reading of 350 mV (+/-10 mV) RMS.
Step 4 While monitoring the amplitude of the recovered audio signal, adjust potentiometer R93 for a
reading of 2.500 (+/-10 mV) VDC.
Step 5 Steps 3 and 4 are interactive adjustments, therefore repeat steps 3 and 4 until further
adjustment is no longer required (i.e. when 350 mV RMS and 2.500 VDC are realized).
Step 6 While monitoring the recovered audio signal at TP1, verify the distortion is less than 3%,
adjust CV4 if necessary to achieve less than 3% distortion. Record this value on the Test
Data Sheet.
Step 7 While monitoring the recovered audio signal at TP1, verify the SINAD is -118 dBm or better.
Record this value on the Test Data Sheet.
Transmit Data
Perform the following steps to adjust transmit data:
Step 1 Use IPMessage to set the transmit power to 0.
Step 2 Using the x=2000,n command of IPMessage to generate transmit data messages while
observing the transmitted signal on the HP RF communications test set, adjust pot RV4 for
minimum frequency error while transmitting data messages.
Step 3 Turn potentiometer RV5 fully counterclockwise.
Step 4 Adjust RV2 for deviation of 4.9 kHz.
Step 5 Using calibrated base station, and monitoring the uplink received data quality on the base
station's Hyperterminal screen, slowly turn RV5 clockwise until consistent data quality
readings of 240 - 248 are achieved using 2000 character test messages. Data quality
reading should not be less than 240 for 2000 character messages.
If unable to reach the data quality readings then ask for Technical Support. Poor data
quality readings are indicative of poor group delay performance, or other defect.
Step 6 Verify transmit deviation, frequency error, and transmitting data messages quality and record
this data on the Test Data Sheet.