MFJ Sound Card Radio Interface (1275/1275m)

1275 Header	Jumper IC729	Jumper IC706(MkII(G))	Jumper FT-817 (100D?)
HD1	6	7	7
HD2	7	5	4
HD3	2,3,4,6,7,8	1,2,3,5,7,8	1,2,3,4,7,8
HD4	1	6	5
HD5	5	4	6
HD6	5	4	6
HD7	1	6	5

Trying to build an adapter to use my
MFJ-1275m with my Icom IC-729

8-pin Mic	Function	RJ45 Mic
1	TX (Mic)	6
2
3	Up/Down (470 Ohm)	2
4
5	PTT	4
6	Ground	5
7	Mic Ground	7
8	RX	3

5-pin DIN	Function
1	Transmit Signal
2	Ground
3	PTT
4	Receive Signal
5 (some models)	External Carrier Detect
Some models have a separate connector for Receive Signal (speaker input). For example, Kantronics KPC-1 has an "Aud In" jack.

DB-9	Function
1	Transmit Signal
2	External Carrier Detect*
3	PTT
4	N/C
5	Receive Signal
6	Ground
7	N/C
8	N/C
9	Ground

* Also used as RxD for software serial port on KPC3+ v8.3

 

DB-9F	DB-9M	Function	Audio Plug (2.5mm)
1	1	DCD
2	3		Tip
3	2		Ring
4	4
5	5	Ground	Sleeve
6	6
7	7
8	8
9	9

DB-9	Function	5-pin DIN
1	Transmit Signal	1
2	External Carrier Detect	5
3	PTT	3
4	N/C
5	Receive Signal	4
6	Ground	2
7	N/C
8	N/C
9	Ground

DB-9	Function
1	SQC squelch signal output.
2	9600 bps data out
3	9600 bps data in
4	1200 bps data out
5	Ground
6	N/C
7	PTT
8	5.0V dc max 50mA output
9	1200 bps data in

DB-9	Function
1	SQC squelch signal output.
2	9600 bps data out
3	9600 bps data in
4	1200 bps data out
5	Ground
6	N/C
7	PTT
8	5.0V dc max 50mA output
9	1200 bps data in

Icom IC-729 8-pin Mic

Mic	Function
1	TX (Mic)
2
3	Up/Down (470 Ohm)
4
5	PTT
6	Ground
7	Mic Ground
8	RX

Icom IC-706 RJ45 Mic

Mic	Function
1	8v (10mA)
2	Up/Down (470 Ohm)
3	AF Out
4	PTT
5	Ground
6	Mic
7	Mic Ground
8	Squelch

 

RS-232

Function	DB-9m Maxon	DB-9 (OT+)	Function
Volume Control	9		N/C
Chanel Select	8		N/C
Power +11.5v	7		N/C
Carrier Detect	6		N/C
Vcc+	5	7	Vcc
Ground	4	6	Ground
PTT	3	3	PTT
Audio Out (Sp)	2	5	Receive Signal
Audio In (Mic)	1	1	Transmit Signal

Pins 4&5 on the radio also have leads to powerpoles so that power can be provided to the radio and OT+.