Tx Audio Routing, Simplified Schematic For Chart 1-4 - Motorola MCS 2000 Service Instructions Manual

9-8

TX Audio Routing, Simplified Schematic for Chart 1-4

1.5Vdc
46mVrms
152mVpp
2.5Vdc
45mVrms
145mVpp
EXT MIC
J0403-13
MIC
VOLTAGE
R0222
100
C0219
10µF
2.5Vdc
R0223
45mVrms
1K 145mVpp
INT MIC
J0405-9
C0427
470pF
December 6, 2004
Troubleshooting TX Audio Routing, Simplified Schematic for Chart 1-4
25KHz, 80mVrms, 1KHz tone
12.5KHz, 80mVrms, 1KHz tone
MIC
VOLTAGE
9.3V
R0231
100
C0222
10µF
2.5Vdc
R0230
45mVrms
1K
139mVpp
R0229
470
C0421
VR0412
470pF
14V
1.5Vdc 2.5Vdc 1.5Vdc
46mVrms 45mVrms 46mVrms
C0218
152mVpp 152mVpp
139mVpp
0.1µF
R0224
470
C0224
VR0411
0.022µF
14V
HEAR CLEAR i
COMP
BUF IN
D3
C0254
10nF
1.5Vdc
46mVrms
C0221
152mVpp
0.1µF
C0223
MIC AMP
0.022µF
OUT
45mVrms
EXT
145mVpp A7
MIC
46mVrms
IN
152mVpp
45mVrms 46mVrms
INT
145mVpp 152mVpp
B8
MIC
IN
U0250
COMP COMP
BUF OUT OUT
PLACED
F2 F3
900 MHz
R0252
ONLY
47.5K
C0251
0.1µF
C0257
10nF
A6 C7
TX
IN
C8
PREMP
C0243
10nF
LIM
IN
E8
2.5Vdc
114mVrms
ASFIC
372mVpp
VCO VCO MOD
U0200
ATTN
H8
1.5Vdc
57mVrms
172mVpp
MAEPF-25959-O
68P81083C20-D