User's Manual

SECTION 4: FACTORY TEST PROCEDURE
M64700G25-FCCRpt.doc Page 27
Adjustment / Alignment Procedures
Receiver Injection
Perform the following steps to adjust the receiver injection and injection frequency:
Step 1 While monitoring the receiver injection frequency at RXINJ1, input the value for the DAC
frequency control for minimum frequency error (+/- 100Hz). Record this value on the Test
Data Sheet.
Step 2 While monitoring the 44.545 MHz 2nd injection frequency at U6 pin 4, adjust trimmer
capacitor CV22 for the maximum amplitude of this injection frequency. The maximum
amplitude must be between -3 to -5 dBm. Record this value on the Test Data Sheet.
Step 3 Repeat Step 2 by monitoring U9 pin 4 and adjusting CV20 for Receiver2 IFLO. Record this
value on the Test Data Sheet.
Receiver 1
Perform the following steps to adjust receiver 1:
Step1 Inject an on-frequency carrier signal with amplitude of -80 dBm, modulated with a 1 kHz test
tone at +/- 5.0 kHz deviation into receiver 1's antenna port.
Step 2 While monitoring the voltage at RSSI1 Test Point with a DMM, adjust trimmer capacitor CV15
and C16 to midway between the points where the oscillation stops.
Step 3 While monitoring the DC level of the recovered modulation; adjust potentiometer RV6 for a
reading of 2.500 VDC +/- 1 mV DC.
Step 4 While monitoring the amplitude of the recovered audio signal, adjust potentiometer RV5 and
RV6 for a reading of 350 mV RMS and 2.500 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 CV15 and CV16 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.
Receiver 2
Perform the following steps to adjust receiver 2:
Step 1 Inject an on-frequency carrier signal with 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 CV6
and CV7 to midway between the points where the oscillation stops.