TM 11-6625-2398-15-3
of continuity checks with a multimeter (para 4-11). The
4-7. Cleaning
schematics, in chapter 6 are to be used as a guide in
a. Transit Case. Inspect the exterior surfaces of the
determining the connections to check for continuity.
transit case. The exterior surfaces should be clean, free
Any cable found to be defective should be sent to higher
of dust, dirt and grease.
category maintenance for repair.
(1) Remove dust and loose dirt with a clean, lint-
4-10. Operator's Repairs and Adjustments
free cloth.
a. Minor Repair of Cables. Repair minor cuts in
WARNING
cable insulation by covering it first with rubber tape and
Cleaning compound is flammable and its
then with friction tape. If cable is broken, refer defective
fumes are toxic.
Provide adequate
cable to higher category maintenance for repair.
ventilation. DO NOT use near a flame.
b. Replacement or Adjustment of Knobs.
(2) Remove grease, and ground-in dirt from the
components. Use a cloth dampened (not wet) with
(1) Replacement. To replace a defective knob,
cleaning compound.
proceed as follows:
(a) Set the knob to its extreme
(3) Use a brush to remove dust or dirt from plugs,
counterclockwise position.
jacks, and knobs.
(b) Loosen setscrews on the defective knob
b. Extender Boards. Periodically clean the extender
and remove the knob from the shaft.
board assemblies with inhibisol cleaning solvent or with
a solution of 70 percent isopropyl alcohol and 30 percent
(c) Place a new knob on the hybrid
distilled water. Using a brush, clean the printed-circuit
attenuator shaft, and line up the zero position on the
contacts with Miller-Stephenson Freon TF Degreaser.
new knob with the zero index of the stationary portion.
Place a new knob on the switch shaft of the front panel
4-8. Touchup Painting Instructions
test adapter, aline the marker of the knob with the first
(counterclockwise) switch position.
Remove rust and corrosion from metal surfaces by
lightly sanding them with fine sandpaper. Brush two thin
(d) Tighten setscrews.
coats of paint (see below) on the bare metal to protect it
from further corrosion. Refer to applicable cleaning and
(2) Adjustment.
To adjust a knob on its shaft
refinishing practices specified in TM 9-213 (Painting
proceed as follows:
Instructions for Field Use). For touchup painting of the
Transit Case, use Light Gray Enamel, Formula No. 11
(a) Tighten the setscrews on the loose knob
per MIL-E-15090, Type II, Class I (Gloss); for touchup
and turn it to its extreme counterclockwise stop.
painting of the Hybrid Attenuator Assembly and Front
Panel Test Adapter use Light Gray Enamel, Formula
(b) Loosen setscrews and line up the zero
No. 11 per MILE-15090, Type II, Class 2 (Semi-gloss).
position of the knob with the zero index of the stationary
portion.
4-9. General Troubleshooting Information
(c) Tighten setscrews.
Troubleshooting this equipment is based upon the
operation of the test facilities set in a hot mock-up
4-11. Continuity Check of Cables, Extender Boards,
configuration to operate the iff set. If, in troubleshooting
and Front Panel Test Adapter (fig. 4-1)
the iff set, certain components of the test facilities set
are defective or suspected of being defective (other
Use Multimeter AN/PSM-6B to perform the continuity
than cables, extender boards or the front panel test
checks. All tests are made with the following control
adapter) higher category maintenance is required.
settings on the multimeter:
Troubleshooting the cables, extender boards and the
front panel test adapter of the test facilities set consists
4-3
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