Furuno FS-1503 - Page 84

5-15
Table 5-3 Measurements (2/2)
Board Name Check Points *Setting Reading Remarks
TX Circuit
EXC OUT A 14 Vp-p PA connected
CHK EXC A 2.4 Vdc CR24-K
Q25: B-GND 0.5 Vp-p
C-GND
A
15 Vp-p
Q25: B-GND 0.65 Vdc
C-GND
B
13 Vdc
2SC3133
TP5 - TP6 0.65 Vp-p 1 MIX MOD AF Input
TP8 - TP9
A
13 Vp-p MIC Input
OSC Circuit
TP1 - TP2 C 0.8 Vp-p 1 Lo (Fo + 54.455 MHz)
TP3 - TP4 C 1.1 Vp-p 2 Lo (54 MHz)
TP7 - TP6 C 1.0 Vp-p 3 Lo (456.5 kHz)
RX Circuit
Q1/2: D-GND 1.2 Vp-p RX RF FET (2SK937)
S-GND
D
0.11 Vp-p
Q1/2: D-GND C 13 Vdc RX RF FET (2SK937)
S-GND C 2 Vdc
U3-7
RF VR
MAX to
MIN
4.2 Vdc to
5.6 Vdc
AGC
U15-1 1.2 Vdc
-2 0.8 Vdc
-3 0 Vdc
-4 6.0 Vdc
TX/RX (05P0666)
-5
D
13 Vdc
AF Power AMP (TDA2003H)
*Use high Z voltmeter.
TP1 - TP2 22 Vp-p 170 kHz
SW REG
(05P668)
Q1: G-TP2
Input:
13.6 V
14 Vp-p 2SK1266 (GATE)