User's Manual

F32700N25.doc Page 15
a. In the main menu select; Antenna, frequency 45 MHz, Reference level
-20dBm, and span=100 kHz.
b. In the RF Gen. menu select; Track, Offset frequency to; (receive
frequency- 45 MHz) (For example 724MHz), Level -50 dBm, and
Port/sweep RF out/invert.
Step2 While monitoring C80 pin1, adjust the capacitors CV7, CV8, CV9, and CV11
to measure; flat, wide, and the maximum level of the signal.
Step3 Set the monitor at RX mode; select the frequency: 769 MHz, Amplitude: -80,
Atten: Hold Off, AFGen1 Freq: 1.00 kHz, AFGen1to: FM 5 kHz, AFGen2Freq:
1.00 kHz, AFGen2 to; Off, Filter1: 300 Hz HPF, Filter2: 3 kHz LPF, Ext Load
R: 600 Ohm, Output Port: RF Out.
Step 4 Connect audio probe to the HI audio port on service monitor.
Step 5 While monitoring the recovered audio signal from pin 7 Of U9, Inject carrier
signal with amplitude of -80 dBm, modulated with a 1 kHz test tone at +/- 5.0
kHz deviation into receiver’s antenna port of the radio.
Step 6 Adjust discriminator CV12 to achieve the minimum distortion (less than 1.5%).
Note that the amplitude of the audio signal should be at the maximum level at
the point of minimum distortion
Step 7 Using IP Message, set the mobile to receiver1 using the command
“receiver=1”.
Step 8 Clip the audio probe to TP1 of the digital board. While monitoring the
amplitude of the recovered audio signal, adjust potentiometer RV3 for reading
of 350 mV RMS.
Step 9 While monitoring the DC level of the recovered audio, adjust potentiometer
RV4 for a reading of 2.500 VDC +/- 10 mV DC.
Step 10 While monitoring the recovered audio signal at TP1, verify that radio performs
12 dB SINAD or higher at -118 dBm input. Reduce the signal level to the input
of the receiver until the SINAD= 12 dB.
Step 11 Record the signal level for 12 dB SINAD, distortion, AC Voltage and DC
voltage on the Test Data Sheet.
Receiver Calibration