MODEM73 is a KISS TNC frontend for the aicodix OFDM modem.

Building

1. Install dependencies

# Debian/Ubuntu/Pi
sudo apt install git build-essential libncurses-dev g++  

2. Clone aiocdix DSP libraries and build.

# Requires DSP, code, and modem libraries 
git clone https://github.com/aicodix/dsp.git
git clone https://github.com/aicodix/code.git
git clone https://github.com/aicodix/modem.git

# Clone modem73
git clone https://github.com/RFnexus/modem73

# Your folders should look like this:
#.../
#├── dsp/           # DSP library (aicodix)
#│   └── ...
#├── code/          # Code library (aicodix)
#│   └── ...
#├── modem/         # Modem library (aicodix)
#│   └── ...
#└── modem73/       # modem73 src
#    └── ...

# Build
cd modem73
make AICODIX_DSP=../dsp AICODIX_CODE=../code MODEM_SRC=../modem
# Optional: move to /usr/local/bin 
sudo make install 

Running & Operations

By default, MODEM73 will listen on port 8001

All of the modes provided by the OFDM modem require a bandwidth of 2400 Hz and work over both FM and SSB.

There are currently four PTT options:

• NONE (speaker/mic over the air)
• Rigctl
• VOX
• Serial

# Start in UI mode
./modem73

# Start in headless mode
./modem73 --headless

# See all options with:
./modem73 --help

PTT options

# Connect to rigctld for PTT control
./modem73 --rigctl localhost:4532

while running rigctld

./modem73 --ptt vox --vox-freq 1200 --vox-lead 500 --vox-tail 150
# 500ms vox lead and 150ms vox tail

./modem73 --ptt com --com-port /dev/ttyUSB0 --com-line rts

Updating

modem73 comes included with a update utility update.sh

To update to the latest version:

./update.sh