Section II. BLOCK DIAGRAM ANALYSIS
1-5. Block Diagram Analysis of System Testing
a. Figure 1-2
is a functional block diagram showing
the test set connected for system testing of AN/GRC-
SM-442A/GRC is to provide all the necessary stimulus
106. Test cable W12 is the only connection required
control, test points, electrical connections, mechanical
between the RT-662/GRC and the AUDIO IN/OUT
coupling, power source, and resistive power loads for
connector on the test set. Test cable W12 connects the
testing Radio Set AN/GRC-106. With standard external
two sets of audio test points, AUDIO IN 600 (ohms) and
test equipment, both GS and depot categories of testing
50 (ohms) and AUDIO OUT 2 WATT and 10 MW, on
can be performed on either the modules or
the front panel of the test set, to the RT-662/GRC. The
subassemblies of the AN/GRC-106 or performance tests
AUDIO IN test points connect an external audio source
of either high or low impedance to the AN/GRC-106.
The AUDIO OUT test points measure the two audio
3349/GRC-106 units separately or as a complete AN/
output voltages of the AN/GRC-106. The test set also
provides for keying the AN/GRC-106 by connecting the
KEY switch, on the front panel of the test set, to the
b. When conducting system tests of the AN/GRC-
RT662/GRC unit through test cable W12.
106, the units being tested are connected directly to the
test set A2 by test cables. For module testing of the
b. Using the SM-442A/GRC to test the RT-
AN/GRC-106, the appropriate test fixture tray is
662/GRC as a separate unit requires audio test cable
required. Direct current (dc) and alternating current
(ac), mechanical coupling, switching information, and
cables are connected: between the RT-662/GRC and
the stimulus that is normally supplied by a complete
the test set. The AM-3349/GRC-106 can also be
radio set are supplied by the test fixture tray to the
checked as a separate unit.
module being tested.
Figure 1-2. Radio Set AN/GRC-106 testing, block diagram.