
3-2
68P02945C75-A
June 1999
Accessory
GTX/GTX LTR/LTS 2000 Portable Radios Service Manual
Maintenance
necessary to touch the microphone cartridge
and associated wiring.
¥ Replacement microphone cartridges should be
kept in conductive packaging until they are
placed in unit.
Maintenance
Refer to the schematic diagram (shown in Figure 3-2),
the exploded view (shown in Figure 3-3), and the parts
lists. Every part in the microphone is identiÞed and
illustrated for assistance in removal and replacement.
If necessary, the external surfaces of the remote speaker
microphone may be cleaned with a 0.5% solution of
mild dishwashing detergent in water (one teaspoon of
detergent in a gallon of water).
Electrical Parts List
HMN9030 Electrical Parts List
REFERENCE
SYMBOL
MOTOROLA
PART NO.
DESCRIPTION
capacitor, Þxed:
µ
F
±
10%; 100 V
un-
less otherwise stated
C1
2113740A53
chip, 82 pF,
±
5%, 50V
C2
2113740A67
chip, 330 pF
±
5%, 50V
C3
2113741A53
chip, .022
µ
F,
±
5%, 50V
C4
2113741B69
chip, .1
µ
F
±
5%, 50V
coil, inductor
L1 thru L4
2462575A02
chip, 680 nH,
±
10%
header:
090989T02
4-pin
switch
:
S1
3905834K06
dome, PTT
miscellaneous:
MK1
0180706Y83
microphone assembly
LS1
5005910P05
speaker
C4
LS1
3.5 mm plug
3.5 mm plug
+
_
S1 PTT
C1
C2
C3
+
_
L2
L4
L1
2.5 mm plug
2.5 mm plug
MK1
L3
( Tip )
( Sleeve )
( Tip )
( Sleeve )
Figure 3-2.
Schematic Diagram
(silk, nylon, etc.) because they contribute to
static buildup.
¥ All electrically powered test equipment should
be grounded. Apply the ground lead from the
test equipment to the unit before connecting the
test probe. Similarly, disconnect the test probe
prior to removing the ground lead.
¥ If the microphone cartridge is removed from
the unit, place it on a conductive surface, such as
a sheet of aluminum foil which is connected to
ground through 100k ohms of resistance.
WARNING
If the aluminum foil is connected directly
to ground, be cautious of possible electri-
cal shock from contacting the foil at the
same time as other electrical circuits.
¥ When soldering, be sure the soldering iron is
grounded
¥ Prior to replacing circuit components or touch-
ing the microphone cartridge, be sure to dis-
charge any static buildup. Since voltage
differences can exist across the human body, it is
recommended that only one hand be used if it is