TM 5-3810-231-12
Probable cause
Possible remedy
Brushes do not make good contact with the slip-rings
on the magnetic clutch shaft unit ................................ ...... Replace the magnetic clutch slip-ring brushes and clean the
slip-ring (para. 116).
56C. Machine Swings Violently and Lacks Control
Probable cause
Possible remedy
Voltage regulator not functioning properly ........................ Check voltage from "A" to "B" (fig. 3) should be 45 to 105, if
zero, replace voltage regulator plug-in unit (para. 150).
Movable graphite brush contact on circuit board of
controller fails to contact segments ................................ .. Replace brush and clean circuit board (para. 149).
56D. Machine Swings Too Slowly in Either Direction
Probable cause
Possible remedy
Crane alternator belts loose . ................................ ............ Adjust belt tension (para. 39).
Voltage regulator contact fingers badly worn or oxidized ... Remove voltage regulator plug-in unit and visually inspect
finger contacts. If faulty replace voltage regulator plug-in
unit (para. 150).
Section VI. RADIO INTERFERENCE SUPPRESSION
NOTE
57. Definitions
Do not pull on the cable or twist the
braided shielding. Gently work the
a. Interference. The term "interference" as used
cable from side to side and free the
herein, applies to electrical disturbances in the radio
rubber seal. Do not use sharp metal
frequency range which are generated by the Model
tools to install the rubber seals.
1125, 60 ton Crawler Crane and which may interfere
with the proper operation of radio receivers or other
electronic equipment.
b. Secondary Suppression Components. These
b. Interference
suppression.
The
term
components have radio interference suppression -
"interference suppression" as used herein, applies to the
functions which are incidental and/or secondary to their
methods used to eliminate or effectively reduce radio
primary function.
interference generated by the Model 1125, 60 ton
Crawler Crane.
60. Replacement of Suppression Components
58.
General Methods Used to Attain Proper
Refer to figure 25 and replace the radio
Suppression
interference suppression components.
61.
Testing
Radio
Interference
Suppression
Essentially, suppression is obtained by providing
a low resistance path to ground for stray currents. The
Components
methods used include shielding the ignition and high
Test the capacitors for leaks and shorts on a
straps, and using capacitors and resistors.
capacitor tester; replace defective capacitors. If test
equipment is not available and interference is indicated,
59. Interference Suppression Components
isolate the cause of interference by the trail-and-error
method of replacing each capacitor in turn until the
cause of interference is located and eliminated.
a. Primary Suppression Components. The primary
suppression components are those whose primary
function is to suppress radio interference.
These
components are described and located in figure 25.
59
