HomeHomebrewThe complete Cable for Digital Modes with the Icom M710

In my last post I outlined the wiring for achieving rig control with the ICOM M710RT (RT is my model) using the Icom Control Panel Application and Ham Radio Integrator from N3ZH. That is nice, in that you can tune the radio with your PC, but you need Audio out from the radio to decode digital signals and you need to be able to put audio into the rig as well in order to send. I’m going to outline how you do that here, it builds directly on the last cable I built.

First off build the Icom M710 control cable in the last past.

To get audio into your PC so the software can hear it you will need an 1/8″ (3.5mm) male to male cord that will reach from the Speaker jack on your M710 to the Line In jack on your PC. My M710RT had a speaker jack coming off of the power cord leading to the remote faceplate. Plug one end of the 1/8″ cord into it and the other end into the Line In on your PC. You need to be careful not to turn the radio up too loud. I have also read you need to put an opt-isolator in this circuit. I’ve not done that, I might do it later, but for now what I have is working. You shoudl now hear your radio through your PC speakers or headphones.

In order to be able to send audio you will also need another 1/8″ (3.5mm) male to whatever cord that is long enough to reach from your Mic jack on your PC to the splices you made in your control cable. This cord is going to plug into the Headphones or Line Out on your PC and and we’re going to splice into the cable we made earlier. Keep one end of the cable with the male end and cut off the other end. You should have a red and white wire and then some un-insulated Shield wire. USe your multimeter to figure out which wire is the TIP wire. Pull back the insulation the TIP wire and connect it to the wire from PIN #1 on the M710 end of the control cable. Connect the bare SHIELD wire to Pin #2 on the M710 control cable.

Your control cable should now have a DB9 connector on one end that goes to the M710 REMOTE port, a Db9 connector on the other end that goes to the PC serial port, and an 1/8″ jack that goes to the headphones\lineout\speaker on your PC. Again, technical guidance calls for an opto-isolation thingy here (I don’t really know why) but my cable works without it.

You can now connect this cable to the M710 and your PC along with the straight male to male wire from your M710 speaker output to the Line In on the PC.

With this cable you will be able to control your Rig, HEAR the digital signals and SEND digital signals. More on that next…


The complete Cable for Digital Modes with the Icom M710 — 5 Comments

  1. Patrick, Why are you using speaker audio out? Schematics show that the Remote port on your Icom M710RT already has audio isolation transformers built in on the MOD and AF signals. Also the opto isolator is an option for the M710 RS422 communications output NMO+ and NMO- not audio signals.

    M710 Remote Dsub 9 connector pin#5 NMI+ to RS232 Dsub 9 pin#3 TX
    M710 Remote Dsub 9 connector pin#7 NMO+ to RS232 Dsub 9 pin#2 RX
    M710 Remote Dsub 9 connector pin#6 NMI- and pin#9 Ground to RS232 Dsub 9 pin#5 GRD

    Do Not connect M710 Remote Dsub 9 pin#8 NMO-

    Connect the RS232 Dsub 9 into a USB to serial converter (Keyspan 19HS USA works)

    HRI isuues CAT start Tx and stop Tx commands over this COM port so you can include the Rx and Tx audio signals in this cable if you use 8 conductor shielded cable.

    • Connect M710 Remote Dsub 9 Pins#1 MOD+ and #2 MOD- to a 600 ohm to 600 ohm audio transformer to the laptop headphones out 3.5mm plug tip and shield.
    • Connect M710 Remote Dsub 9 pins#3 AF+ and #4 AF- to a 600 ohm to 600 ohm audio transformer to the laptop MIC in 3.5mm plug tip and shield.

    Make sure you check the M710 Set Mode menu parameters Remote Interface is set to Dsub not pin or clone and the Remote ID is 01 by turning the rigs power on while holding in the Function and 1 buttons.

    Opto isolating the NMO+ and NMO- would be better but it works without it just do not ground the NMO-. Add ferrites if needed.

    This cable will not yet work with Winmor RMS Express because it does not issue start Tx and stop Tx CAT commands. An interface from laptop to M710 Marine and General versions’ ACC(1) pin#5 AF, pin#4 MOD, pin#2 GND and pin#3 SEND is needed to run RMS express.

    This cable works with http://groups.yahoo.com/group/N3ZH_software/

    Ham Radio Integrator’s Winmor keyboarding application and HRI’s CAT control allows Icom Marine HF SSB tranceivers to use all the features of Ham Radio Deluxe’s DM780.

    • Tom, I finally changed my cable and I think from the improved appearance of the waterfall, that I’m actually getting clearer audio.
      To modify the cable I created I added one additional 1/8″ Jack and connected the TIP to the Remote DB9 pin #3 and the Shield of the same to the remote DB9 pin #4. Works like a charm!


  2. I use the Speaker output of the M710, because I’m actually passing it through an External DSP unit, the BHI Ltd NEIM1031, works great eliminates much static from my received signals.

    Thanks for the heads up about the RMS\Winmor stuff. I’ll need to sit down and decode your post when I get to trying that.

  3. Has anyone tried to use a Signalink USB with an Icom M710 and provided rig control for HRD? Thanks in advance.