How to Download, Install, and Configure MMTTY for Ham Radio MMTTY is the gold standard for Amateur Radio RTTY (Radioteletype) operation. Created by Mako Mori (JE3HHT), this free software uses your computer’s sound card to modulate and demodulate RTTY signals with incredible efficiency.
This guide will walk you through getting MMTTY up, running, and perfectly configured for your ham radio shack. 1. Download MMTTY
Always download MMTTY from trusted, active repositories to ensure you have the latest compatibility patches for modern operating systems.
Visit the official repository: Go to the official MMTTY page hosted by DXLab or the hamsoft site.
Select the installer: Download the latest full installer package (typically an .exe file).
Get the EXTFSK extension (Optional): If you plan to use a hardware COM port or USB-to-serial adapter for direct FSK keying, download the EXTFSK.DLL file as well. 2. Install the Software
The installation process is straightforward, but directory placement matters for modern Windows permissions.
Launch the installer: Double-click the downloaded setup file.
Choose the directory: It is highly recommended to install MMTTY directly to your root directory (e.g., C:\MMTTY) instead of the Program Files folder. This prevents Windows User Account Control (UAC) from blocking configuration saves.
Complete the wizard: Follow the on-screen prompts and click Finish.
Add extensions: If you downloaded EXTFSK.DLL, copy and paste that file directly into your main MMTTY installation folder. 3. Configure Audio and Sound Card Settings
MMTTY relies entirely on your sound card to “hear” and “speak” RTTY tones. Open MMTTY. Click on Option in the top menu, then select Setup MMTTY. Click on the Misc tab.
In the Sound Card section, select Rx 16-bit for optimal decoding accuracy.
Look at the Device ID section. Set your Receive (Rx) and Transmit (Tx) audio sources to match the specific sound card interface connected to your radio (e.g., SignaLink, Digirig, or your radio’s internal USB audio codec). 4. Configure Demodulator and RTTY Standards
To successfully decode signals, MMTTY must match standard amateur radio conventions. Navigate to the Demodulator tab in the Setup window.
Set the Baud Rate to 45.45 (the standard for amateur radio HF RTTY). Set the Shift to 170 Hz. Set the Mark Frequency to 2125 Hz (standard high tones).
Ensure the Mark/Space logic matches your operating style. If your decoded text looks like gibberish on a known good signal, you may need to click the REV (Reverse) button on the main screen later. 5. Configure Transmit (TX) and Keying Method
You must tell MMTTY how to make your radio transmit. There are two primary methods: AFSK (Audio Frequency Shift Keying) and FSK (Frequency Shift Keying). Method A: AFSK (Easiest / Standard USB Sound Cards) Go to the TX tab.
Set the PTT Port to the COM port associated with your interface’s rig control/PTT line.
If using a VOX-based interface like a SignaLink USB, set the PTT Port to NONE (the hardware handles the switching when audio plays). Method B: True FSK (Requires EXTFSK) In the TX tab, locate the PTT Port dropdown. Select EXTFSK.
A small auxiliary window will pop up. Define which pin on your serial port handles the FSK data (usually TXD or DTR) and which handles the PTT (usually RTS). 6. Testing and Operation
Receiving: Tune your transceiver to an active RTTY frequency (e.g., 14.080 MHz on 20 meters). Look at MMTTY’s XY scope (the circular tuning indicator). Tune your radio until the two intersecting ellipses align horizontally and vertically. You should see text scrolling in the RX window.
Transmitting: Press the TX button in MMTTY. Verify that your radio keys up and transmits the classic dual-tone warble. Keep your radio’s ALC (Automatic Level Control) low to ensure a clean, un-distorted signal. If you want to optimize your station further, let me know: What transceiver model you are using
Which audio interface connects your radio to the PC (e.g., internal USB, SignaLink, Digirig)
Whether you prefer logging standalone or integrating MMTTY into a logging program like N1MM or DXLab
I can provide the exact step-by-step settings for your specific hardware setup.
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