TM 5-6665-202-13
Chart 5-1. Troubleshooting - Continued
Chart 5-1. Troubleshooting - Continued
MALFUNCTION
MALFUNCTION
TEST OR INSPECTION
TEST OR INSPECTION
CORRECTIVE ACTION
CORRECTIVE ACTION
5. PROPER ADJUSTMENT CANNOT BE OBTAINED
3. SET CUTS OFF AND ON DURING OPERATION -
WITH FINE X CONTROL
CONTINUED
Step 1. Check for defective Fine X control.
Step 4. Check for defective headset.
Remove Fine X control resistor (19, fig. 6-5)
Test headset and replace if either or both
and test. Replace a defective Fine X
earphones are defective.
control resistor.
Step 5. Check for defective capacitor.
Step 2. Check for defective terminal board.
Remove and test capacitor. Replace a defective
Remove modules and test terminal board.
capacitor.
Replace a defective terminal board.
Step 6. Check for defective power selector switch.
6. PROPER ADJUSTMENT CANNOT BE OBTAINED
WITH FINE R CONTROL.
in the "ON" position. Replace switch if test
Step 1. Check for defective Fine R control resistor.
indicates an "open" circuit.
4. SIGNAL DOES NOT INCREASE AS DETECTOR HEAD
Remove Fine R control resistor (16, fig. 6-5)
and test. Replace a defective Fine R
COMES CLOSER TO METAL OBJECT.
control resistor.
Step 1. Check for defective detector head.
Step 2. Check for defective terminal board.
Test transmitter coil and receiver coil located
Remove modules and test terminal board.
in detector head and replace coils if defective.
Replace terminal board if defective.
Step 2. Check for defective terminal board.
7. SET FAILS SENSITIVITY TEST
Remove modules and test terminal board.
Replace a defective terminal board.
Step 1. Check battery; replace if necessary.
Step 2. Check variometer phasing adjustment using
the phasing fixture and magnetite tube.
REMOVAL AND INSTALLATION OF MAJOR COMPONENTS
Section III.
AND AUXILIARIES
5-6. Headset
b. Test. Refer to Table 5-1 and perform the point-to-
a. Removal.
point test applicable to each of the four modules.
(1) Remove the housing from the transmitter
Replace a defective module. When performing these
tests, use an electronic AC RMS Voltmeter (1-B, Appen-
(2) Refer to figure 5-1 and remove the headset.
dix C) and Test Leads (2-B, Appendix C).
b. Installation.
c. Installation. Refer to paragraph 4-11b and install
(1) Refer to figure 5-1 and install the headset.
the four modules in the transmitter and receiver
(2) Install the housing on the transmitter (para
assembly.
4-11b).
d. Variometer Phasing Adjustment. Adjust the de-
tecting set with the detection head positioned on the
5-7. Control Box
phasing fixture (figure 5-4). The phasing fixture will
a. Removal. Refer to figure 5-2 and remove the
permit optimizing the phase adjustment so that the
control box.
presence of magnetite will produce the smallest back-
b. Installation. Refer to figure 5-2 and install the
ground signal possible. The phasing fixture should be
control box.
used whenever a variometer module not previously
phased to the particular detector is inserted in the
5-8. Detector Head and Balance Coil Assembly
detector. The phasing fixture and detector head should
a. Removal. Refer to figure 5-3 and remove the
rest on a non-metallic table or stand whose construc-
detector head and balance coil assembly.
tion can be of plastic or wood except there can be no
b. Installation. Refer to figure 5-3 and install the
metal fasteners used. Keep metallic objects (watches,
detector head and balance coil assembly.
rings, belt buckles, tools, metal lab stools, etc.) away
from the detection head at least 2 1/2 feet in all
5-9. Modules
directions. A non-metallic alignment tool (plastic wand
a. Removal. Refer to paragraph 4-11b and remove
with a small metal blade mounted in the end) should be
the four modules from the transmitter and receiver
used for any adjustments. The following steps will
assembly.
enable the phase adjustment to be properly made.
5 - 2 Change 2
