be necessary to warm the brush with a soldering
pin punch having a tip approximately .05 inch
iron or soak the brush and tip of the bakelite
sleeve in glyptal solvent.
d. Commutator (E, fig. 195). Clean
mutator with a rubber eraser, preferably one
h. Synchronous Motor, Parts Description (fig. 105).
containing grit, such as an ink eraser. Do not
use emery or sandpaper.
e. Synchronous Motor Field Coils (F, fig. 105).
In emergencies, a defective coil can be discon-
nected and the motor operated on three of its four
coils. The power will be reduced, making it
difficult to phase. Motors with serial numbers
above 1000 have six poles; those below this serial
number have four poles. The removal of one
coil does not materially reduce the motor power.
When ordering replacement parts, be sure to select
the proper replacement coil. For replacement of
synchronous motor coils and bushings on syn-
chronous motors KBA-1 and KBA-2, use the
appropriate Signal Corps Motor Coil Replacement
f. Lead-In Bushings. Defective lead-in bush-
ings are the most common causes of motor coils
burning out. Keep them clean at all times and,
when possible, replace then with nylon bushings.
Nylon bushings are supplied on KBA-1 motors.
Ceramic bushings are supplied on motor KBA-2.
Refer to e above for information on replacement
in motors supplied with Facsimile Transceivers
TT-1/TXC-1 and TT-1A/TXC-1, remove the
armature extension (A) of the start magnet and
disconnect the brush leads from the terminal
(H). If the bakelite sleeve (B) is in good con-
dition, replace only the carbon brush (C) and its
flexible lead. The brush can be pulled loose
from the bakelite sleeve. In some cases, it may