The Icom IC-9700 works well as a Winlink Express radio using a software TNC. In this example, the software TNC Soundmodem by UZ7HO ver 1.05 on a Windows 10 64bit workstation. This short guide assumes your IC-9700 (with firmware ver 1.21) has been setup and connected to a Windows PC. In this example the IC-9700 is USB attached to the workstation and is on COM-6, the USB cable will be used for sound mic/speaker and PTT.
Download software TNC file soundmodem105.zip from http://uz7.ho.ua/packetradio.htm and unzip the contents into a folder on your Windows PC – note there is NO installer it runs direct from the folder that you placed it into. Launch soundmodem.exe and configure the Modem Settings – you only care about the Modem Filers for Ch: A (Fig-1):
Next in soundmodem setup the Settings to interface with your IC-9700, be sure to set your PTT Port to the correct COM port on your PC – this is the same COM port you would use to clone your config using the free Icom software CS-9700 off the Japan Icom site. Be sure to select the proper Output device and Input device (Fig 2):
Next you will want to setup the connectors in the 9700 to “talk” to the Windows PC running soundmodem and Winlink Express. Here are the Connector settings I am using (Download The PDF) :
Make sure the IC-9700 is in FM-D mode and on a frequency of a nearby Winlink Express Gateway, when soundmodem is running and setup for AFSK AX.25 1200bd you should see a waterfall with activity in the soundmodem window (Fig 3):
Here are the Packet Winlink Session Settings for reference Fig 4:
Here is a short video of the operation using the software-based TNC and the Icom IC-9700 connecting to a Winlink Express RMS gateway via RF: