Kenwood NXR-1800 Service Manual page 104

LEVEL DIAGRAM
TX-RX UNIT
Receiver Section
5
RF (E2: 435.05MHz / E: 485.05MHz)
-119dBm -122dBm
D707
ANT L762
E2:D708
L763 E2:D709
L764 D711 C843 IC703 C839
C825
4
BPF BPF
LNA
To make measurements in the AF section, connect the AC level meter.
(ANT input: –53dBm, 1kHz FM, 1.5kHz DEV (Narrow))
This model doesn't have Audio AMP and SP. AF load must be 100kΩ (Audio analyzer input).
In the RF section, use 1000pF coupling capacitor.
(The display shows the SSG input value required to obtain 12dB SINAD)
3
Transmitter Section
AF (1kHz)
280mVrms
Wide 5k:1.0Vp-p
Narrow:0.5Vp-p
2
IC75
D-SUB25 TA
9-Pin
AF AMP
1
A
-119dBm -106dBm
-104dBm
D703, 704
E2:D715,717 L714 IC702 C819 IC701
BPF
BALUN IF AMP
RX 1st MIX
(1kHz)
Wide 5k:0.25Vp-p
Narrow:0.125Vp-p
IC42 IC33 IC670
R2037
MPU
SSI
CODEC CODEC
/DSP
R2076
MOD: 1kHz/1.5kHz DEV (Analog Narrow) , 1kHz/3kHz DEV (Analog Wide 5k)
MOD 1kHz/1.5kHz DEV
B C
(No.RA094<Rev.002>) 2-4
1st IF (45.0MHz)
-110dBm -113.5dBm
-90dBm
Q701 C800 Q700
C814 XF700 C803 C797
BPF
IF AMP IF AMP
MCF
AF
( : -53dBm, 1kHz FM, 1.5kHz
RF
(
AF
+4dB
E2:400-435MHz
E:450-485MHz
Q2001
Q2010
L VCO C2102 C2066
COUPLER
H VCO TX VCO
BUFF AMP
E2:435-470MHz
TX PLL Fin
E:485-520MHz
1kHz/3kHz DEV
D
2-4 (No.RA094<Rev.002>)
IC42
IC700 IC33
SSI
IF IC MPU/DSP CODEC
AC
( ))
100kΩ
1000pF
12dB SINAD SSG
RF (E2: 435.1MHz / E: 485.1MHz)
-3dBm +15dBm +20dBm
C3087 IC3023 C3090 Q3067 C3162 Q3065
DRV
PRE DRV PRE DRV
AMP
AMP AMP2
5k
E F
AF (1kHz)
400mVrms
IC74 C379
C386
D-SUB25
11-Pin
AF AMP
)
50W 40W
+33dBm
+47dBm +46dBm
C3300
C3106 Q3069
C3301
FINAL
LPF
AMP
G