Comnet MLS II MLSH041, Руководство по обслуживанию

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LBI-38425A ALIGNMENT AND TROUBLESHOOTING PROCEDURES
24
5.3.2 Alignment Procedure
STEP
TEST
POINT
TUNING
CONTROL
METER
READING PROCEDURE
1 TP501 9.0 ± 0.2 VDC Connect the DC Voltmeter to TP501.
2 TP504 L511 See Procedure Connect RF signal probe from the
frequency counter to TP504. Check
for a reading of 81.745 MHz ±200
Hz.
3 TP503 L513 See Procedure Set the signal generator on the 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.
4 J701-1
-6
See Procedure Move P551 from J551-1 & 2 to 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.
5 J701-1 L501
L503
See Procedure Set the output signal level of RF
signal generator so as to obtain 12 dB
SINAD at audio output.
Adjust coils L501 and L503 to obtain
maximum 12 dB SINAD sensitivity.
Return P551 to J551-1, 2.