TM 11-6625-847-45
DC/DC CONVERTER CONV/REG TEST switches REG
and CONV and caused to flow through an external
NOTE
ammeter. The ammeter is connected across test points
Prefix reference designators in tray A1A2 with
HI and CONV LOW for current measurements of the
reference designators A1A2, unless otherwise
converter section and test points HI and REG LOW for
specified.
current measurements of the regulator section of the
module DC/DC CONVERTER TEST SELECTOR switch
S4 controls the pin selection of DC/DC CONVERTER
inputs, resistive loads, and test points available on tray
test points HI and LO for voltage measurements under
A1A2 for testing the receiver IF module, the receiver
specified loads at the connector pins J9 as follows:
audio module, and the transmitter IF and audio module
position 1 monitors the +27-volt dc input voltage from
of the RT-662/GRC.
the test set; position 2 connects the test points to the
output of the +20-volt dc regulator at the emitter of
b. The +27-volt dc input to tray A1A2 from the test
transistor A2Q1; position 3 monitors the + 125-volt dc at
set is controlled by POWER switch S3. In the ON
pin 6 of J9; position 4 monitors the -33 volt dc at pin 14
position, POWER switch S3 supplies the +27-volt dc
of J9, position 5 connects the test points across 6.3-volt
input voltage to module connectors J8, pin 8, and J25,
ac at pins 1 and 9 of J9. Transistor A2Q1 replaces the
pin 28 (fig. 6-8); to POWER indicator DS1; to KCVR
+20-volt dc series regulator transistor of the dc-to-dc
AUDIO test point SQUELCH SYNC; and to pin 40 of
converter and regulator module that is mounted on the
connector J1, energizing the converter section of dc-to-
chassis of the RT-162/GRC unit and disconnected from
dc converter and regulator module A3 on the test set.
the regulator section when the module is removed. The
The +20-volt dc input from the test set is connected
output of the +20-volt dc regulator is controlled by three-
directly to module connectors J8, pin 7; J17, pin 1; and
position DC/DC CONVERTER LOAD SELECT switch
J25, pin 1; to amplifier assembly A1; and to AGC SYNC
S6. The positions of the LOAD SELECT switch are
switch S6.
designated 100, 500, and 600 for resistive loads
providing current drains of 100 milliamperes (ma), 500
ma, and 600 ma, respectively. Test point J11 is for
c. When testing the receiver audio module of the
measuring the output voltage of the +20-volt dc
RT-662/GRC, the external audio signal from the
regulator.
COMMON AUDIO 600 Ω IN connector on tray A1A2 is
connected to AUDIO GAIN control variable resistor R1,
and through the ON position of the SQUELCH SYNC
c. When testing the noise blanker subassembly of
switch S1, to receiver audio module connector J8.
the RT-662/GRC, the NOISE BLANKER 1 USEC
SQUELCH ON/OFF switch S2 controls the squelch
PULSE IN MODULE, PULSE OUT MODULE, and
circuitry of the receiver audio module by supplying a
PULSE OUT TEST connectors provide the necessary
ground to pin 13 of J8. The test set SERV SEL switch
mating connectors and impedance loads for connecting
supplies a ground to pin 5 of connector J8 when in the
external test equipment with BNC connectors to the
FSK and CW positions. OUTPUTS test points 2 WAIT
noise blanker subassembly microdot connectors.
and 1O MW monitor the output audio signal of the
receiver audio module.
d. When testing the RF amplifier module of the
RT-62/GRC, the voltage at the wiper of RF AMPL AGC
ADJ control resistor R1 is connected through the ON
module of the RT-662/GRC, the external audio signal
contacts of RF AMP AGC switch N5 as simulated
from the COMMON AUDIO 600 Ω IN connector is
automatic gain control (age) voltage to pin 3 of J15.
connected to pin 16 of transmitter IF and audio module
The voltage as controlled by RF AMPL AGC ADJ at pin
connector J25. A 1.750-mc signal is supplied to pin A2
3 of J15 is the simulated age input voltage to the rf
of J25 from the test set IF OSCILLATOR (1) 1.75 MC
amplifier module.
module. From the mixer module of the test set, pin A3
of connector J25 receives a
1-16 Common Module Tray A1A2
1-14
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