Alignment Procedure; Fixed Squelch Adjustment - GE MLSH041 Maintenance Manual

5.3.2 Alignment Procedure

5.3.3 Fixed Squelch Adjustment

LBI-38438A
ALIGNMENT AND TROUBLESHOOTING PROCEDURES
TEST TUNING
STEP POINT CONTROL
1 TP501
2 TP503 L513
5 J701-1
-6
4 J701-1 L503
-6 L505
L510
1. Disable Channel Guard, if present, (ground J701-7). Set squelch control RV531 full
CCW.
2. Connect a signal generator to antenna jack J1 and adjust for nominal 8 dB SINAD
signal.
3. Adjust squelch control RV531 to maximum squelch. Receiver must be muted.
4. Adjust squelch control RV531 slowly until receiver unmutes.
METER
READING
9.0 ± 0.2 Connect the DC Voltmeter to TP501.
VDC
See Set the signal generator on the
Procedure receive frequency with ±3 kHz
deviation and 1 kHz modulation.
Set the RF signal level to 1000
microvolts.
Connect the audio level meter (use a
high impedance meter) to TP503.
Adjust the L513 until audio output
level becomes maximum.
See Move P551 from J551-1 & 2 to
Procedure J551-2 & 3 in receiver unit.
Terminate J701-1 & -6 with a 4 ohm,
6 watt resistor.
Connect the Audio Level Meter and
Distortion Analyzer input across the
resistor.
Adjust the volume control for 4 W
output (4.0 Vrms) using Audio Level
Meter.
See Set the output signal level of RF
Procedure signal generator so as to obtain 12
dB SINAD at audio output.
Adjust coils L503, L505 and L510 to
obtain maximum 12 dB SINAD
sensitivity.
Return P551 to J551-1, 2.
PROCEDURE
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