IFR FM/AM-500, Maintenance Manual

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On the FM/AM-500A, the output of U3323B is connected to multi­
plexer U3313. The input signal to U3313, which is selected by
the Modulation Meter Range Switch, is then connected directly
to multiplexer U3324B and, normally, through U3314B to the
meter. However, when a peak power or modulation function is
selected, U3324B couples the output of U3313 through the peak
detector, then through U3314B and to the meter.
7-10-2 PREPARATION FOR TESTING
A. REMOVAL AND DISASSEMBLY
Remove the Receiver Audio PC Board as outlined in Section 6.
No disassembly is required.
B. REQUIRED TEST EQUIPMENT
1 - Oscilloscope •••••••••••••••• 10 MHz Bandwidth
1 - Digital Multimeter •••••••••. 100 KO/V
1 - Extender Cable ••••••••.••••• 26 Pin M/F Connectors
1 - 12
11
,
20 GA Lead ••••••••••••• E-Z Mini Hook
C. PREPARATION
1. Make the following initial control settings (Refer to Con­
trols, Indicator and Connector Drawing in Section 1).
KEY CONTROL
4 Modulation Meter Range
Switch
9 Modulation Mode Select
Switch
11 RF LEVEL Attenuator
Control
12 RF LEVEL FINE Adjust
Control
13 VAR TONE Level Control
14 VAR TONE Select Switch
15 1 kHz TONE Select Switch
16 1 kHz TONE Level Control
17 Power Switch
18 VAR TONE FREQ Thumbwheels
24 GEN/LOCK Control
25 Frequency Error Meter
Range Switch
26 GEN/REC Switch
27 VOLUME Control
28 SQUELCH Control
7-62
SETTING
"BATT TEST"
"FM WIDE"
1
1 -110 dBm"
Fully ccw
"OFF"
Fully cw
Fully cw
"OFF
II
"OFF
II
11
1300.0
11
"LOCK"
"RF 10 K"
"GEN"
Fully ccw
Fully cw