Kenwood TH-K20A, Service Manual

Page: 32 / 40

TH-K20A/K20E
32
LEVEL DIAGRAM
T
o mak
e measurements in the AF section, connect the A
C le
vel meter
.
(ANT input:
–53dBm,1kHz FM, 1.5kHz De
v (Narro
w).)
In the RF section, use a high impedance probe
. (ANT input:
–53dBm, MOD off).
A
G is set to the MIC input becomes 1.5kHz De
v, at 1kHz MOD
. (Narro
w)
T
o mak
e measurements in the AF section, connect the A
C le
vel meter
.
In the RF section, use a 1000pF coupling capacitor
.
Receiver Section T
ransmitter Section
FM IF
SYSTEM
DAC
SSG
–53dBm
ANT
–56.1dBm
–74.2dBm
–66.8dBm
–50.8dBm
–52.8dBm
–40.3dBm
–57.1dBm
–29.1dBm
31mV
rms
27mV
rms
2.4V
rms
2.3V
rms
2.0V
rms
C265
C256
C248
C273
C228
C223
C217
C322
C381
C357
SP
500mW
Q303
Q305
IC307
IC300
IC200
Q202
XF200
MIXER
Q203
Q204
RF (CENTER FREQUENCY)
IF1 (38.85MHz)
IF2
450kHz
AF (1kHz)
IC300
DAC
AF
AMP
C22
–29.1dBm
VCO
C27
C34
C113
7.3dBm
C134
34.9dBm
ANT
50
Ω
MIC
8.0mV
rms
4.4mV
rms
37.4dBm
C101
12.2dBm
C107
Q4
Q5
RXLo
D7
D8
Q101
Q102
Q103
AF (1kHz)
RF (CENTER FREQUENCY)
R303
Q3
+
–9.1dBm
–1.8dBm
–2.5dBm