Kenwood TH-22A Service Manual page 38

TH-22A/AT/E
TERMINAL FUNCTION
TX-RX unit (A/4): TX-RX ——>TX-RX unit (B/4): CONTROL
Connector No. Pin No. Pin name ; Function
CN1, 203 1 MUTE Audio mute signal (TX-RX line)
2 SB Power supply
3 NC
4 BUSY Squelch control signal
§ AF RX audio
6 SM S-meter level
7 Ci Signalling AF signal
8 UP Encoder up signal
9 3M Reference power supply voltage 3.5 V
10 DN Encoder down signal
13 APC APC voltage
12 RB Power module power supply voliage
13 EP PLL IC enable signal
14 ASB AF power amplifier AVR input voltage
15 DT Serial data signal
16 E GND
17 UL PLL unlock signal
18 3R Receiver power supply
19 CK Clock signal
20 3C PLL IC, VCO power supply
ai TX VCO oscillation frequency switching signal
22 3T Transmitter power supply
23 MOD Modulation signal
TX-RX unit (A/4): TX-RX —— VCO unit
Connector No. Pin No. Pin name Function
_CN1, 2 CV Lock voltage
MOD Modulation signal
3C VCO power supply voltage
TX VCO oscillation frequency switching signal
OUTP fin VCO output
OUT RF output
TX-RX unit (B/4): CONTROL <—> PTT
Connector No. Pin No. Pin name Function
CN201 1 COM Key matrix input
CN301 2 MONI Key matrix output, Monitor switch
3 LAMP Key matrix output, Lamp switch
4 PTT PTT switch signal, "L": TX; "H": RX
5 E GND
6 E GND
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