TM 32-5835-005-14 & P
GENERAL
SUPPORT
MAINTENANCE
INSTRUCTIONS
Section
I.
GENERAL
8-1. Scope of General Support Mainten-
NOTE
ance.
Before using the multimeter for resis-
Complete rebuild of the AN/UNH-17A and/
tance checks of transistor circuits,
check the open circuit voltage across
or its individual components may be acc-
omplished by general support maintenance
the multimeter test leads. Do not use
facilities when authorized. Rebuild
the multimeter if the open circuit
voltage exceeds 1.5 volts. Also, since
procedures of the AN/UNH-17A will in-
clude all repairs, rebuild replacement
the RXI range normally connects the
multimeter integral battery directly
and testing operations necessary to
across the test leads, the comparatively
make the equipment suitable for return
high current (50 ma or more) may damage
to supply systems stocks for reissue
the transistor circuits under test. As
to using organizations as equipment
a general rule, it is not recommended
equivalent to new material. Detailed
that the RXI range of any multimeter be
procedures for accomplishing the repair
used when testing low power transistor
and rebuild operations as necessary,
circuits. Never connect test equip-
will be established by the maintenance
ment (other than multimeters and VTVMs)
facility performing the work.
outputs directly to a transistor circuit,
use a coupling capacitor.
8-2. Voltage and Resistance Measurements
8-3. Waveforms.
NOTE
When making waveform observations for
This equipment is transistorized. Ob-
direct comparison with illustrations
serve all precautions given to prevent
transistor damage. Make voltage meas-
contained within this manual, observe
the conditions under which the waveforms
urements in this equipment only as
were obtained.
specified. When measuring voltage,
use tape or sleeving to insulate the
entire test prod except the extreme
tip. A momentary short circuit can
damage a transistor. Use the schematic
diagram to find normal voltage indic-
ations and compare them with test con-
ditions.
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