3-125. If any part of Coil Gear Assembly 1A8A3 or Coil Assembly 1A8A5 has been replaced, reset end
stop switches 1A8A3S1 and S2 as follows:
Refer to DETAIL B of figure 3-28. With coupling (P/N 755017A8339) secured only to the coil
shaft and not to the pinion shaft (P/N 755017A8333-2) shown in DETAIL A of figure 3-28, rotate
the coil until the coil contact is against the mechanical stop located at the gear-train end of the coil.
Turn the coil rotor back 1/4 turn to locate the coil contact away from the mechanical stop and in
line with the top left coil bar. Do not allow coil to turn.
Rotate modified gear (P/N 755017A4563), shown in DETAIL A of figure 3-28, counterclockwise
(CCW) until the
clicks, and snug one of the set screws that secures coupling (P/N 755017A8339) to pinion shaft
Turn the modified gear (P/N 755017A4553) clockwise to reach the other set screw. Remove the
set screw and apply Loctite Grade E to the set screw hole, then reinstall the set screw securely.
Repeat step 4 for the other set screw.
3-127. Repair of the power amplifier in the field can in many cases be accomplished by replacement of a
faulty assembly. The replacement, described in the following paragraphs can be carried out by field
maintenance activities having the proper tools and repair parts. Detailed repair of printed wiring boards
should only be done by technicians trained and authorized to make such repairs, as described in paragraphs
3-128. GENERAL REPAIR INFORMATION
3-129. Most power amplifier major assemblies and subassemblies are readily accessible for replacement. The
removal and access instructions of paragraphs 3-15 through 3-45 apply to all major assemblies and sub-
assemblies authorized for removal by field maintenance activities. The following standard maintenance
practices should be followed:
Use the tools specified to prevent damage to hardware and components, and to ensure that hardware
is properly tightened during reassembly.
When removing cables, tag each lead for easy identification at reassembly.
When replacing components with several connections, sketch the component connections before
3-131. The following disassembly instructions apply to ALC Module Assembly 1A7, Tune Detector Module
Assembly 1Al0, RF Driver Module Assembly 1A11, Static Power Inverter Assembly 1A12, and HF Module
Assembly 1A13 after their removal from Case Assembly 1A14. Disassembly of Tank Circuit Module
Assembly 1A8 is not authorized for Fourth Echelon Maintenance Activities.
DISASSEMBLY OF ALC MODULE
Refer to figure 3-36. Use a No. 1 Phillips screwdriver to loosen and remove the four cover retaining
screws. Remove the cover from the frame assembly.
To remove Tune Load PWB Assembly 1A7A1, use a No. 1 Phillips screwdriver to loosen and remove
the four retaining screws, lockwashers, and flatwashers that secure Tune Load PWB Assembly
1A7A1 to the frame assembly. Pull the pwb away from the frame assembly carefully. Access for
component replacement is now available.