TM 11-6625-847-45
the antenna coupler assembly on the AM-349/GRC-106.
1-22. Synthesizer Test Tray A1A3 Electronic
b.
The + 27-volt dc input to tray A1A4 from
Circuits
the test set is controlled by POWER switch S1. The ON
position, POWER switch S1 supplies + 27-volt dc
primary power to POWER indicator DS1; to CONTROL
Note. Where partial reference designators are
TEST indicators A1 through A5, B1 through B5, and C1
used, prefix with synthesizer test tray A1A3 reference
through C5; to GRID DRIVE control resistors R3 and
designator A1A3, unless otherwise specified
A1R4; and to pin 40 of connector J1, energizing the
a. Amplifier modules AR1 through AR5 are used to
converter section of dc-to-dc converter and regulator
amplify the RF output signals of the RT-662/GRC
module AS on the test set.
modules on tray A1A3. The amplifier module consists
of POWER switch S1, VOLT ADJ control RI, and two-
stage transistor amplifier board A1.
3349/GRC-106, INPUT CURRENT switch S6 permits s
current measurements of the input +27-volt dc primary
b. The RF input to the amplifier module is
power across test points HI and LO TEST SELECTOR
controlled by AMPL ON/OFF switch S1. With S1 in the
switch S8 controls the selection of test points HI and
OFF position, the input at J1 to the amplifier module is
LOA for voltage measurements of the inverter assembly
connected directly to output connectors J3 and J2 by
at connector J12. Position 1 of TEST SELECTOR
passing the amplifier board. With S1 in the ON position,
switch S8 connects the test points to +27-volt dc primary
the rf input signal to the amplifier module is coupled to
power at 10 AMP fuse F1. When switch S8 is in
the base of first stage transistor A1Q1 by capacitor
position 2, the test points are connected to pin 9 of J12
A1Q2. The amplified output of A1Q1 is sampled by the
for measuring the voltage drop across load resistor R9
position of the wiper arm of VOLT ADJ collector load
in the test set. With the switch in position 3, the test
resistor R1. The sampled portion of the amplifier signal
points measure the voltage drop across resistor A2R1 at
is the input to the base of second amplifier A1Q2. The
pin 6 of J12. Position 4 of the TEST SELECTOR switch
amplifier output of A1Q2 is coupled from the emitter by
connects the test points to pin 13 of J12 for measuring
capacitor A1C5 through the bandpass filter, consisting of
the voltage drop across resistors A2R2 and A2R3.
inductor A1L1 and amplifier A1C6, on amplifier modules
With the switch in position 5, the test points connect to
AR1, AR2, AR4, and AR5, to contact terminal 4 of
pin 1 and 2 of J12 for measuring the voltage drop across
AMPL ON/OFF switch S1. On amplifier module AR3,
resistor R8 on the test set. EXTERNAL BLOWER
inductor A1L1 and capacitor A1C6 are connected in a
switch S7 in the HI position connects pin 10, connector
band reject configuration (fig. 6-12) between the output
J12, and in the LO position, pin 11, connector J12, to
of A1Q2 and ground. The ON position, the AMPL
load resistor R9 on the test set.
ON/OFF switch connects the amplified output of A1Q2
to output connects 33 and J2.
d. When testing the AM-349/GRC-106 front panel
assembly at connector J2, CONTROL TEST indicator
C5 indicates a ground at pin 23 of connector J2.
1-23. Converter and Control Tray A1 A4
CONTROL TEST indicators A1 through AS indicate
grounds at pins 6 through 10 of J2, respectively.
Note. Prefix reference designation with converter and
CONTROL TEST indictors B1 through B4 indicate
control tray A1A4 reference designator A1A4, unless
grounds at pins 17, 18, 14, and 20 of J2, respectively.
otherwise specified.
CONTROL TEST indicators C2, C3, and C4 indicate
voltages at pins 4, 11, and 12 of connector J2,
a. Figure 1-14 shows the various controls, indicators,
respectively. PA METER TEST GRID DRIVE control
connectors stimulus inputs, resistive loads, and test
RS controls the level of the dc voltage to pin 25 of
points available on tray A1A4 for testing the inverter
connector J2. PA METER TEST ANTENNA LOAD/
assembly, the front panel assembly, and the inputs of
1-21
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