Cables for ICOM ID-5100

Hello! Any chance of an ID-5100 cable for digital modes?

I ordered the icom RJ45 cable and plugged into Speaker A and the mic spots. Other end to audio port of Digirig. I can report that I was able to connect via WINLINK over FM.


To be clear …

The TRS plug into speaker A and the RJ-45 into the microphone jack. Or did I misunderstand the “mic spot”?

Further clarification/confirmation … by speaker A, you mean speaker 1?

Are you using a PC or RPi?

Tnx … Tom VE3NY

1 Like

You have rephrased it perfectly. This was using a mini windows 11 computer. I will test with a pi tomorrow

Wow … this seems like a simple way to configure ID-5100 for digital modes. What digital modes are you running? Which version of Digirig are you using?

Regarding RPi, I look forward to your experience but I can try now since I also have mini PC running W10

tnx … Tom VE3NY

Hello Mike,

What was your experience with The RPi?


Ok, thanks for making this product and posting the link.

1 Like

Can anybody with ICOM ID-5100 confirm if the serial port connection works with Digirig:


This will require Digirig in RS-232 and regular TRS m/m cable (e.g. stereo patch cord).

Per manual on page 7-15 this can be used for data communication (internal TNC?).

I have the radio but I believe my DigiRig is not RS-232. I looked and see that with some solering I can change to RS-232.

If both of my DigiRigs weren’t in use I’d give it a try. @K0TX - I’d be happy to help if you’ve got a DR that we could ship back and forth, to use for testing.

The image you show is used for “cloning”, setting parameters, DV Fast Data, and Firmware updates. I have not used that Data port as it’s easier to use a memory card for what I need. I added a capture of the circuit for the data port that I found but I have not verified it as correct.

CI-V control:
To control the rig with Fldigi I selected hamlib as it is the only one with ID-5100 support listed.
I used hamlib to control the rig in a very basic sense (frequency) with the DigiRig. For the CI-V control use SP2 on the ID-5100. The ring is both TX and RX (half duplex) and the sleeve is ground. So I wired the ID-5100 SP2 port ring to both the Tip & Ring1 on the DigiRig. Then the sleeves are connected for the ground. I was able to use hamlib command line to read the freq. and then use fldigi to read and set it. (Don’t forget to enable the CI-V port in the radio). I left the other CI-V comm settings at default. Also before I wired this up I checked the voltages on SP2 ring to ground and found about 3.4 volts peak to peak on the port during transition of data from the radio.

Other: I have the Digirig ICOM RJ-45 cable plugged into the Mic port and the SP1 port.

This screenshot is from page 13-16 of the full manual. SP2 port for C-IV control of the Rig

Unverified Schematic of the Data Port:

1 Like

Thanks for the clarification, Paul.
Sounds like with Digirig configured for CI-V and the CI-V cable (part of ICOM kit, or a trivial homebrew) we should be all set for ID-5100 CAT control.

While there is no specific Audio+CAT cable kit for ID-5100 in store, please feel free to reach out for mix-and-match arrangement.

David KQ4BDU reports that he got his ID-5100 CAT control going with the stock 1:1 TRS audio cable by modifying the Digirig’s serial port connections:

I’m yet to confirm if the regular jumpers CI-V configuration with Digirig’s CI-V cable will also work.

Update: I’ve been able to use Winlink with VaraFM and Winlink with Soundmodem successfully as well as FLDigi/Hamlib. I use the volume control on the radio to control the input level to the DigiRig (squelch at 0) and have the sound card output for the DigiRig set to 0dB. It has worked great with some really weak signals (VaraFM says about -0.5dB Sig-Noise and shows red). In my final CAT - CI-V cable I’ve added a jack for the external SP2 ( see diagram that says “No speaker is necessary…”) for my small Icom speaker. At times when testing digital modes it’s been useful to switch to the B band (I always use A for the digital mode) to listen to the local repeater to see if anyone is discussing the current issues. (I don’t have an extra radio to listen) Other than that I haven’t found much use for having SP2 plugged into a speaker.

1 Like

Exactly what settings are you using with Soundmodem to get it to work? I am currently trying to get my IC-2730 to work with soundmodem and PinpointAPRS (using network Kiss). I have the digirig cable for the IC-2730 but can’t seem to get it to transmit. Receive works just fine and it is decoding APRS packets.

Hi Tom, picture of settings for sound modem (apologies for the not so great photo). In the sound control panel I have both the speaker(s) level and the mic level set at 0dB (right click slider to change it to dB). I just remembered that on some software the serial port part of the digirig - in my case COM3 can be set to various handshake lines. The digirig uses RTS (even if nothing is plugged into the digirig serial port - it goes through the MIC cable). You may want to check the devices setup to make sure the com port for the digirig is listed under com ports and check the port name (my apologies if that is too much detail.)

I currently have been trying with the TRRS from the radio plugged into the digirig’s audio socket, should it be plugged into the serial socket instead?

I don’t think you would need the serial socket unless you want to set frequencies. It may be in the software settings for your application. For example my PTT is com3 in software. Even though the DigiRig has a separate serial port socket it still uses one of the serial wires through the audio socket to press the PTT. The cable going into your Mic. Port on the radio. The RTS line if my memory serves. If you look in Windows device manager under the section for com ports you should see the port name it has registered. In some apps this is configured in a separate place from the sound cards. Note that I have two radios and they all attempt to register on the same port name as the DigiRig. So go to the advanced dialog in the serial port settings in the device manager and change the port name to an unused one as needed. Sorry I’m doing this from memory at the moment so I don’t have a picture. I can post some pics - just let me know. Also most of my programs like VaraFM have to have the sound card interface set every time I start them. Somehow the program loses its setting and the wrong sound card is selected. So I check this every time I start up.

I returned to this project now that cables described above have arrived.

RJ45 to microphone jack,
TRS to Speaker 1,
TRRS to Digirig.

Running Winlink Express/Vara FM on a MiniPC.

All working as it should. Audio levels are very high record/playback on the 5100 but when dialled back, everything working fine.



I received my DigiRig CI-V. I loaded the drivers and could see the com port and USB PnP audio. I got the RJ-45 cable and I got the cable from the Icom Kit. I hooked up the Rj-45 to the mic jack and the TRS to SP1 and the TRRS to the audio port. The cable from the icom kit, I plugged into sp2 and the serial port on the digirig. The radio went into trasmit mode and the digirig got hot. Now, I can longer see the comport or the audio ports. So, I’m afraid I might have toasted it.

Anyone have suggestions? I’m wanting to use this on the ID-5100 for Winlink Packet & Vara, as well as Fldigi. Any configuration steps is greatly appreciated.



PM me for repair arrangements for your Digirig.
Next time around I would recommend setting up audio/PTT first without connecting CAT control and once that is all up and running then deal with latter. This way if something goes wrong you can narrow it down to a single concern.