Homebrewed Icom to LDG Tuner cable (LDG IC-PAC)


I recently bought an Icom IC-718 HF Transceiver with LDG AT-100ProII Automatic Tuner. Though this tuner automatically senses the frequency output and tunes itself on transmit, it also has an interfacing option to connect to many of the Transceiver brands like Icom, Yaesu, Alinco, etc to tune to the current operating frequency with a touch of a button from the Transceiver itself.  I realized the option would come really handy for everyday use, but It was too late.  The cable isn’t available in India and ordering one from the US costs a lot of shipping (twice the price of the product).  So the only option left was making one.

It looks fairly easy to homebrew this cable if a P3-Molex connector is available. As that too wasn’t available I hacked a Molex connector from a PC SMPS Molex to Sata converter to use it with our Tuner interface cable.

PC SMPS Molex to SATA converter

ldg_icom_auto_tuner_cable_interfaceHeres the wiring diagram for making the interface as listed on the LDG Electronics website.


Cut a groove on one side of the Molex connector as per the below picture. Connect Pin 1 (from Groove) of Molex to tip of the Stereo Jack, Pin to to Ring and Pin 4 to Ground. Also connect Pin 3 of Molex to Center core of the power jack and another wire from pin 4 to the Ground of Power jack.


Here’s the completed cable. It uses a 3.5mm Stereo male Audio jack, Shielded 2 pair stereo audio cable and the same Power cable which came with the Tuner (red in below picture).

Icom IC-718 to LDG AT100-Proii interface cable
Completed Cable

Made this for under Rs100/$2 🙂  Let me know if you were successful making one and leave your comments below for any improvements or suggestions.

Update: A cable for Yaesu rigs is documented here.

Amogh Desai

Amogh Desai

A System Admin by profession, is a tech buff and a licensed Amateur Radio operator with callsign VU3DES. He is interested in Technology, Amateur radio, Electronics home-brewing, FOSS, Photography and everything tech. He uses this blog to share his views and ideas with people sharing similar interests.
Amogh Desai


  1. Hello. Could you please guide me how to homebrew an interface cable for my yaesu ftdx 1200 and ldg at 600 pro ii.
    De vu2ekj


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