TM 11-6625-821-45
REPAIRS AND ALIGNMENT
Section I. REPAIRS
the part before removing it. Replace
the part in the same position.
a. General. Subparagraphs b and c below
(5) When tightening the two setscrews in
provide parts replacement techniques for the
a collar-type clamp, the setscrews must
converter and cable simulator circuits in Test
be tightened against the center of the
Set, Radio TS-2502/ARM-93. Parts for the
gear (or other mechanical parts)
other circuits in TS2502/ARM93 can be eas-
quarter segments.
ily replaced. The following general precautions
b. Parts Replacement for Converter Circuit.
should be observed when replacing parts in
this equipment.
(1) When soldering or unsoldering com-
(2) Remove the two screws from the cover
ponents, solder quickly to allow as
that shields the converter circuit (fig.
little heat conduction as possible.
Whenever wiring permits, use a heat
(3) Lift the cover away from the test set.
sink (such as long-nosed pliers) be-
(4) Replace the defective parts (a above).
tween the solder joint and the part.
(5) Replace the cover over the converter
Use approximately the same length
circuit and secure it with the two
and dress of leads as used originally.
screws.
(2) When the soldering iron is used with
(6) Replace the test set front panel (para
ac, use an isolation transformer be-
tween the iron and the Line. Check
c. Parts Replacement for Cable Simulator
soldering irons for shorts to the iron
Circuit.
tip before using.
(1) Remove the test set front panel (para
(3) In some cases, power transistors are
mounted on heat sinks. When replac-
(2) Remove four screws from the plate
ing power transistors, always replace
that covers the shield in which the ca-
the insulating washer between the
ble simulator circuit is mounted (fig.
transistors and the heat sink if an in-
sulator is used. Before installing the
(3) Replace the defective parts (a above).
mica or fiber washers, treat them with
(4) Replace the plate over the shield of
a film of silicone fluid or equivalent
the cable simulator circuit and secure
to help in the transfer of heat. After
with the four screws.
the transistor is mounted and before
(5) Replace the test set front panel (para
making connections, check from
transistor case to ground for effective
insulation.
(4) Whenever an electrical part, such as
a. Procedures for removing and disassem-
a resistor, capacitor, or coil is to be
bling major component in the test set are
removed, note the exact position of
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