1. Check the COM Ports
After connecting the radio via USB, first check the assigned COM ports in Windows Device Manager → Ports (COM & LPT). In my case:
| FT-991A | FTX-1 |
| COM5 – Enhanced COM Port | COM8 – Enhanced COM Port |
| COM6 – Standard COM Port | COM11 – Standard COM Port |
Note: COM port numbers are assigned by Windows, so they may be different on your PC.
2. N1MM Logger+ Configuration
For this setup, I used a fresh installation of both N1MM Logger+ and MMTTY, with no previous settings carried over.
In the main N1MM Logger+ window, go to:
Config → Configure Ports, Mode Control, Winkey, etc…
In the Hardware tab:
| • Operating mode: SO1V (Single Operator, One VFO) |
| • Port: COM8 (Enhanced COM Port) |
| • Radio: FTX-1 |
| • Digi: unchecked |
| • CW/Other: unchecked |
Note: Your COM port number may be different.
3. Yaesu FTX-1 COM Port Settings
After clicking Set next to the FTX-1 COM port, configure the port as shown below:
| • Speed: 38400 |
| • Parity: N |
| • DataBits: 8 |
| • Stop Bits: 1 |
| • DTR (pin 4): Always Off |
| • RTS (pin 7): Always Off |
| • Radio Nr: 1 |
| • PTT Delay: 30 ms |
| • Radio Polling Rate: Normal |
| • Enable Both Hardware & Software PTT: checked |
| • PTT via Radio Command Digital Mode: checked |
Leave the other options unchecked and click OK.
Note: Not all of these settings necessarily affect RTTY operation, but this is the configuration I used and successfully tested.
4. Digital Modes – MMTTY Setup
Open the Digital Modes tab and configure DI-1 MMTTY Setup as follows:
| • Digital Interface 1 – TU Type: Soundcard |
| • MMTTY Mode: FSK |
| • MMTTY Path: C:\Ham\MMTTY_FTX-1\mmtty.exe |
Use Select to locate the mmtty.exe file.
In my setup, I wanted to keep separate MMTTY configurations for the FT-991A and FTX-1. I therefore made a complete copy of the C:\Ham\MMTTY folder, including all its files, and renamed the copy to MMTTY_FTX-1. For the FTX-1, I then selected:
C:\Ham\MMTTY_FTX-1\mmtty.exe
This is not required for RTTY operation. It is simply a convenient way to maintain different MMTTY settings for the two radios. If you do not need separate configurations, you can use the standard MMTTY installation and select C:\Ham\MMTTY\mmtty.exe instead.
5. Mode Control – MMTTY Setup
Open the Mode Control tab. No special changes were required here for this RTTY setup, but the settings are included for reference and to show the complete configuration.
| • Mode recorded in log: Use radio mode (default) |
| • RTTY – Radio 1 / VFO A: RTTY |
| • DIGI – Radio 1 / VFO A: USB |
| • Always use packet spot mode: unchecked |
These are the default settings used in my installation. No changes were necessary here for RTTY operation.
6. MMTTY Configuration
Now we will move on to the MMTTY configuration itself.
In the MMTTY RTTY Engine window, click Option(O) in the top menu. We will configure the required MMTTY settings step by step as shown below.
7. MMTTY – Demodulator
In Option(O) → Setup MMTTY, open the Demodulator tab.
No special changes were required here. Just check that the basic RTTY parameters are set as follows:
| • Mark: 2125 Hz |
| • Shift: 170 Hz |
| • Fixes: 45.45 baud – checked |
The Mark (2125 Hz) and Shift (170 Hz) values are also set to the same values in the FTX-1.
The other settings were left at their default values as shown in the screenshot.
8. MMTTY – Decode
Open the Decode tab.
No changes were required here. The default settings were used and are shown in the screenshot for reference and completeness of the configuration.
9. MMTTY – TX
Open the TX tab. This is an important part of the FSK configuration.
Under PTT & FSK, change the Port setting to:
EXTFSK64
The other settings were left unchanged as shown in the screenshot.
Do not close the Setup window yet. Click Radio command – this opens another configuration window, which we will set up in the next step.
10. MMTTY – Radio Command
In the Radio command window, configure the communication with the FTX-1 as follows:
| • Port: COM11 (Standard COM Port) |
| • Baud: 38400 |
| • DTR/RTS – PTT: checked |
| • Frequency offset: OFF |
| • Group: Yaesu FT 9000, 2000, 991, 891, 950, 450 |
The Data length, Stop, Parity and Commands settings were left unchanged and should be set as shown in the screenshot.
Although the FTX-1 is not listed in the available Group options, I used Yaesu FT 9000, 2000, 991, 891, 950, 450, and this configuration worked correctly.
Click OK when finished.
11. MMTTY – Misc
Open the Misc tab and use the following settings:
| • Device Identifiers – RX: 3 (see below) |
| • Device Identifiers – TX: 3 (see below) |
| • Clock: 12000 Hz |
| • Sound loopback: Int. |
| • Tx Port: Sound + COM-TxD (FSK) |
The Device Identifiers determine which sound devices MMTTY uses for RX and TX. In my FTX-1 setup, both are set to 3.
These numbers are assigned according to the audio devices available in your PC, so they may be different on another system. The Device Identifiers are linked to the devices selected on the SoundCard tab – changing the identifier effectively selects a different audio input or output device.
If no received signal appears in the MMTTY display even though the correct sound card appears to be selected, check the RX Device Identifier and try the available values until the radio’s audio signal appears.
I set the TX Device Identifier to the same value as RX (3). For this FSK configuration, the TX audio device is less important than it would be for AFSK, since the actual RTTY keying data is sent via FSK rather than being generated as an audio tone by the sound card.
The Clock is set to 12000 Hz, which is a commonly used setting for MMTTY with N1MM Logger+.
Finally, under Tx Port, select Sound + COM-TxD (FSK). This is the setting used in my working FTX-1 configuration.
12. MMTTY – SoundCard
Open the SoundCard tab and select the USB audio device belonging to the FTX-1.
| • Reception: Microphone (USB Audio Device) |
| • Transmission: Speakers (USB Audio Device) |
The exact device names may be different on your PC. For Reception, select the USB audio input associated with the FTX-1. This provides the received audio from the radio to MMTTY for decoding.
In my setup, I also selected the corresponding Speakers (USB Audio Device) for Transmission. However, when operating in FSK, the transmission sound device is not required for generating the RTTY signal, since the actual FSK keying is handled separately.
If you have more than one USB audio device connected, make sure you select the one belonging to the correct radio.
13. Yaesu FTX-1 – Radio Settings
Open RADIO SETTING → MODE RTTY and use the following settings:
| • RPTT SELECT: RTS |
| • MARK FREQUENCY: 2125 Hz |
| • SHIFT FREQUENCY: 170 Hz |
| • POLARITY TX: NOR |
The most important change here is RPTT SELECT = RTS, which allows the RTS line of the USB virtual COM port to control RTTY transmission.
I left POLARITY TX = NOR. The MARK FREQUENCY = 2125 Hz and SHIFT FREQUENCY = 170 Hz settings correspond to the values used in MMTTY.
The Yaesu FTX-1 operating manual also specifies 2125 Hz for the Mark frequency and 170 Hz for the Shift frequency as the standard settings for RTTY operation, so these values match both the radio and MMTTY configuration.
The other RTTY settings were left unchanged. Unlike the FT-991A, the FTX-1 provides these RTTY-related settings together directly under RADIO SETTING → MODE RTTY.
14. EXTFSK64 Configuration
Finally, configure the EXTFSK64 window for the FTX-1.
Use the following settings:
| • Port: COM11 (Standard COM Port) |
| • FSK output: DTR |
| • PTT output: RTS |
| • Inv. FSK: checked |
| • Inv. PTT: unchecked |
The port number may be different on your PC. Select the Standard COM Port assigned to the FTX-1 – in my case this is COM11. The EXTFSK64 window should show Status: OK.
For my FTX-1, the working combination is FSK output = DTR and PTT output = RTS.
There is one important difference compared with my FT-991A setup: on the FTX-1 I had to enable Inv. FSK. With Inv. FSK unchecked, the radio transmitted and produced RF output, but stations I called did not respond correctly. After enabling Inv. FSK, the transmitted FSK polarity was correct and RTTY contacts worked normally.
Therefore, in my working FTX-1 configuration, Inv. FSK is checked, while Inv. PTT remains unchecked.
The Yaesu manual confirms that the FTX-1 Standard COM Port can be used for transmit control and digital operation via RTS/DTR. The Inv. FSK setting itself is handled by EXTFSK64 and was determined experimentally in this setup.
15. Final Note
The settings described in this guide are based on my own working configuration and have been successfully tested on the air. However, every PC and radio setup can be slightly different – COM port numbers, USB audio device identifiers, drivers, or other settings may vary.
Therefore, some adjustments may be necessary for your particular setup.
I hope this guide helps you get RTTY working with N1MM Logger+ and MMTTY without too much trial and error. I would be very happy to receive your feedback and hear whether this setup works for you as well.
