Cables for ICOM M-803 (marine SSB and HAM transciver)


I have a brand new ICOM M-803 a dual role transciver (MARINE SSB and HAM). This unit has been designed to use any of a PACOR modems. I have no itentions to follow this road. I want to use WINLINK, PAT, VARA together with my LINUX box.

M-803 has a dedicated 9 pin serial port to connect with a computer. Its pins are as follow:

1 DCD Inputs terminal for carrier detection.

2 RXD Inputs terminal for receive data.
NMEA-OUT NMEA0183 ver 4.10 data output.

3TXD Outputs transmit data.
NMEA-IN NMEA0183 ver 4.10 data input.

4 DTR Outputs data terminal ready signal.
5 GND Connected to ground.
6 DSR Inputs terminal for a data-set-ready signal.
7 RTS Outputs request-to-send data.
8 CTS Inputs terminal for clear-to-send data.
9 NC No connection.

Its serial port for modem connection (PACTOR):

1 MOD+
Modulation input from an external
terminal unit.
Input impedance: More than 600 Ω
Input level: Approximately
0.77 V rms
2 MOD– Coaxial ground for MOD+. –
3 GND Ground for digital equipment. –
4 AF+
AF detector output for an external
terminal unit.
Output impedance: Less than 600 Ω
Output level: More than
770 mV rms
5 AF– Coaxial ground for AF+. –
6 GND Ground for digital equipment. –
7 NC No connection. –
Ground this pin to transmit. Ground level: –0.5 to 0.8 V
Input current: Less than 20 mA
9 GND Ground for digital equipment. –
REMOTE Pin Pin name Description

Finally, its ACC (round) ports pinout:

ACC Pin Pin name Description Specification
1 CWK CW and FSK keying input. Input level: –0.5 to 0.8 V
2 AF GND Ground line for AF signal. –
Input/Output pin.
Ground this pin to transmit.
Ground level: –0.5 to 0.8 V
Input current: Less than 20 mA
Modulator input.
Usable when pin 3 is grounded.
Input impedance: More than 10 kΩ
Input level: Approximately
100mV rms
5 AF
AF detector output.
Fixed, regardless of [VOL] position.
Output impedance: Less than 4.7 kΩ
Output level: 100–300 mV rms
6 NC No connection. –
7 13.6 V 13.6 V output when power is ON. Output current: Maximum 1 A
ALC voltage input. Control voltage: –3 to 0 V
Input impedance: More than 10 kΩ

Is it possible to create a set of cables to control this radio?

with the best regards,


Yes, we can figure out the cable for this radio.
Is there a table/chart version of this for easier interpretation?

Found the charts/tables in your email. Thank you:


So the audio cable will be to DIN8:

DIN8 pin 2 (AF GND) → 3.5mm TRRS sleeve (GND)
DIN8 pin 3 (SEND) → 3.5mm TRRS ring2 (PTT)
DIN8 pin 4 (MOD) → 3.5mm TRRS ring1 (RIG_AFIN)
DIN8 pin 5 (AF) → 3.5mm TRRS (RIG_AFOUT)

Alternatively audio can be to AF/MOD connector:

DB9 pin 1 (MOD+) → 3.5mm TRRS ring1 (RIG_AFIN)
DB9 pin 2 (MOD-) →
DB9 pin 3 (GND) →
DB9 pin 5 (AF-) →
DB9 pin 6 (GND) →
DB9 pin 9 (GND) → 3.5mm TRRS sleeve (GND)
DB9 pin 4 (AF+) → 3.5mm TRRS tip (RIG_AFOUT)
DB9 pin 8 (SEND) → 3.5mm TRRS ring2 (PTT)

The serial CAT cable will be to REMOTE connector:
DB9 pin2 (RXD) → 3.5mm TRRS tip (RIG_RXD)
DB9 pin3 (TXD) → 3.5mm TRRS ring1 (RIG_TXD)
DB9 pin5 (GND) → 3.5mm TRRS sleeve (GND)
DB9 pin7 (RTS) →
DB9 pin8 (CTS)

Hi, I am impressed with the speed you responded. This is very quick indeed.
Now, I have another question - how much will this cost digirig + the Serial CAT + ACC cables?


I’d recommend you try building the cable at home or with somebody at your local club.
You can also check with if you prefer to outsource this project.


building cables is OK but I have no idea what end connectors to use where. I assume one cable with have DB9 male and the other will have the round ACC 8 pins but what on the other end of each cable and how one end relates to the other? could you provide a diagram or a sketch?


You’ll have two cables each with DB9 on one end (Radio) and 3.5mm TRRS connector on the other end (Digirig).

Hi Denis, this is the last question I have. Where to get the wire and other parts to build these cables?


Hi Denis,

I was wrong, I have one more question- which model of digirig to order - the one labeled for ICOM, right? I just want to make sure,



I got all parts to build cables

Re. parts: for prototyping and small scale build I source the components from Amazon/eBay/Aliexpress. For the cable build I typically start with the cable that already has a correct connector on one side. You can look for DB9 cable that has all needed pins wired or TRRS cable.

Re. Digirig configuration: The serial connection being DB9 and using the standard RS-232 pinout I would go with RS-232 configuration for this radio

Denis, I got the cables sorted out.
Is the DigiRig configured for ICoM the one i need to.order?

ent from Yahoo Mail on Android

Digirig configuration for this radio is RS-232

Just ordered d8977

1 Like