driver CR4 in the transmitter circuit (see figure 1-12), causing LED
CR3 to generate an output optical pulse 10 5 nanoseconds wide at 1064
nanometers. The LED output is diffused and collimated to illuminate
the receiving optics in the LR. For 2 TGT and RCVR 2 PULSE modes, a
second pulse is required. This is accomplished by the triggering of
the 2-targets pulse generator U1A, through driver Q2.
This in turn
connects to the LED driver CR1 in the transmitter circuit, causing
LED CR3 to generate a second optical pulse with the same
characteristics, at a time delay of 0.67 0.33 microseconds,
equivalent to a target separation of 100 50 meters.
TARGET SYNC PULSE (J4), RCVR SYNC PULSE (J3), and LASER PULSE (J2)
are generated as appropriate and are available for testing and
troubleshooting. Figure 1-14 illustrates a simplified block diagram
of the operational interface of the LR and the LR Test Set
components.
PART C - DIRECT SUPPORT MAINTENANCE INSTRUCTIONS
This part of the lesson provides instructions on the testing,
troubleshooting, and maintenance of the LR Test Set.
These
procedures include conducting voltage and resistance measurements,
pulse
checks,
visual
inspection,
and
a
pass/fail
test.
Troubleshooting consists of following a step-by-step troubleshooting
chart and performing the indicated corrective maintenance.
This
lesson intersperses appropriate warnings, cautions, and notes to
avoid personnel injury and equipment damage.
In those cases where fixing the trouble is beyond the scope of direct
support level maintenance, send the LR Test Set to the depot.
In
such cases, the LR Test Set must be fully assembled and complete.
1.
Voltage and Resistance Measurements.
In order to perform the voltage and resistance measurements, you must
remove the LR Tester from its case.
To remove the LR Tester, you
remove the case cover (figure 1-9, item 6), loosen and remove the ten
mounting screws (figure 1-9, item 7), and lift the LR Tester out of
the base (figure 1-9, item 20).
The measurements described below are the circuit performance
standards you use when testing and troubleshooting.
The test
conditions under which the measurements are obtained are also given.
To perform the test and repair of the LR Test Set, you will need the
equipment listed in figure 1-15. This equipment is not furnished as
a part of TK-100/G or TK-105/G.
22
OD1716
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