Kenwood TKR-750, Service Manual

Page: 49 / 101

TKR-750
49
Connector Terminal Terminal I/O Terminal function
No. No. Name
3 8CL I 8V input through the ripple filter
4 CV I RX PLL lock voltage
5 9CL I 9V input through the ripple filter
6 MO I Modulation signal input
CN351 1 VO O TX VCO output
2 GND – Ground
ACC 25 pin D-sub Connector
Connector Terminal Terminal I/O Terminal function
No. No. Name
1 NC – No connection
2 RXD2 I Serial data to radio
3 TXD2 O Serial data from radio
4 AI1 I Programmable function input 1
5 AI2 I Programmable function input 2
6 AI3 I Programmable function input 3
7 DG – Control line ground
8 TD I TX data input (data or signalling)
Input impedance: 600
Ω
Coupling: AC coupling
Deviation: 0.75kHz (wide)/
0.35kHz (Narrow)
(100Hz 0.5Vp-p input)
9 TA I TX audio input (voice)
Input impedance: 600
Ω
Coupling: AC coupling
Frequency response: Pre-
emphasis curve
Deviation: 60% deviation
(1kHz 280mVrms
±
25mV input)
10 RD O RX data output (voice & data)
Output impedance: 1k
Ω
or less
Coupling: AC coupling
Non-squelched
Frequency response:
±
2.5dB at
10~3000Hz
Output level: 70~90mVrms
(standard modulation)
11 RA O RX audio output (voice)
Output impedance: 1k
Ω
or less
Coupling: AC coupling
Squelched
Frequency response: De-
emphasis curve
Output level: 360~440mVrms
(standard modulation)
12 RXG – RX signal ground
(for RA,RD ground only)
Connector Terminal Terminal I/O Terminal function
No. No. Name
13 SPM I Speaker mute signal input
“L”: Mute on
14 NC - No connection
15 EMON I External monitor switch input
“L”: Monitor on, “H”: Monitor off
16 EPTT I External press-to-talk switch input
“L”: PTT on, “H”: PTT off
17 SC O Squelch control output
“L”: Busy, “H”: Not busy
18 NC - No connection
19 TXG - TX signal ground
(for TA,TD ground only)
20 AIO1 I/O Programmable function input/output 1
21 AIO2 I/O Programmable function input/output 2
22 AIO3 I/O Programmable function input/output 3
23 AIO4 I/O Programmable function input/output 4
24 AIO5 I/O Programmable function input/output 5
25 AIO6 I/O Programmable function input/output 6
ACC 15 pin Connector
Connector Terminal Terminal I/O Terminal function
No. No. Name
1 SB O Power supply output after power
switch; 1A maximum
2 SB O Power supply output after power
switch; 1A maximum
3 NC – No connection
4 GND – Ground
5 GND – Ground
6 SPG – Speaker ground
7 RD O RX data output (Equal to D-sub
connector terminal No. 10.)
8 RSSI O RSSI output (Analog signal output)
9 SPI I Internal speaker input
10 AO1 O Auxiliary output 1
Open collector. Low : 150mA max.
11 AO2 O Auxiliary output 2
Open collector. Low : 150mA max.
12 SPO O External speaker output
13 AO3 O Auxiliary output 3
14 AO4 O Auxiliary output 4
15 AO5 O Auxiliary output 5
13 12 11 10 9 8 7 6 5 4 3 2 1
20 19 18 17 16 25 24 23 22 21 15 14
13 10 7 4 1
14 11 8 5 2
15 12 9 6 3
TERMINAL FUNCTION