Level Diagram - Kenwood TM-281A Service Manual

TM-281A
Receiver Section
W : –123.5dBm
N : –123.5dBm
ANT
BPF
Transmitter Section
TX-RX Unit
(Display)
MIC
To make measurements in the AF section, connect the AC level meter.
AG is set so that MIC input becomes 3kHz/1.5kHz (Wide/Narrow) DEV at 1kHz MOD.
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LEVEL DIAGRAM

Center Frequency
W : –120.0dBm W : –103.5dBm
N : –120.0dBm N : –104.0dBm
Q505
D
G2
BPF
S
G1
W/N
4.5mVrms (2.0mVrms for M4-type)
W/N W/N
0.11Vrms 1.62Vrms
IC703 IC703
6
2 1 7
W : –107.5dBm
N : –108.5dBm
Q504
D
G2
G1 S
To make measurements in the RF section, connect the RF level meter
In the RF section, use a 0.01μF coupling capacitor.
(The display shows the SSG input value required to obtain 12dB SINA
TX-RX Unit
W/N W/N
1.32Vrms 1.46Vrms
IC704 IC704
5
3 1 7 2
49.95MHz
W : –80.5dBm
N : –78.0dBm
W : –109.0dBm
W : –97.0dBm
N : –109.5dBm N : –96.0dBm
XF501
Q503
W/N W : 0.63Vrms W : 0.36Vrms
1.19Vrms
N : 0.31Vrms N : 0.18Vrms
IC706 IC706
1
9 8 9
450kHz
CF501
/CF502
IC501
20
TX-RX
IC705
Q6
10
To make