Yaesu FT-891, FT8, USB-C Mac, PS/2 cable

There was a lot involved in getting this working so I thought I would write a post about getting the Yaesu FT-891 to work digital modes (FT8 in this case) with a new Mac the only has USB-C ports. There are probably other ways to do it but I think what I am describing will be the lowest cost route.

First, here are the settings in the FT-891 menu system that I ended up using:

• 05-06 CAT RATE – 9600bps
• 05-07 CAT TOT – 100msec
• 05-08 CAT RTS – ENABLE
• 07-12 PC KEYING – RTS
• 08-01 DATA MODE – OTHERS
• 08-03 OTHER DISP – 1500Hz
• 08-04 OTHER SHIFT – 1500Hz
• 08-05 DATA LCUT FREQ – OFF
• 08-07 DATA HCUT FREQ – OFF
• 08-09 DATA IN SELECT – REAR
• 08-10 DATA PTT SELECT – RTS
• 08-11 DATA OUT LEVEL – 50 (some sites recommended 10 for this, I hardly received any signals at 10, use the WSJT-X waterfall colors to calibrate this)
• 08-12 DATA BFO – USB
• 16-14 DATA DATA GAIN – 50 (this is the default, I didn’t change it)
• There’s also WDH on the FUNCTION-1 menu, I am not sure that this effects DATA mode(I think 08-05 and 08-07 override it) but you can set this to max (3000Hz)

See the Yaesu FT-891 Advance Manual for information on these settings.

Next step is to get CAT control working. I would have an antenna or dummy load connected to the radio as if you don’t have all the settings right there’s the possibility of it going into transmit mode. The FT-891 has a USB-B port on the back, most commonly used on printers. I tried using an old USB printer cable and a USB-C adapter to the Mac but this didn’t work. I’ve had issues with a couple of USB devices using the adapter so it may work for you. I ended up purchasing a USB-C printer cable(USB-B on one end and USB-C on the other). After obtaining the cable, OSX requires the Silicon Labs UART driver for the serial communication between the Mac and the radio to work. The driver can be found here:
https://www.silabs.com/products/development-tools/software/usb-to-uart-bridge-vcp-drivers
It’s a fairly standard Mac driver install and may require security authorization and a reboot to get it fully working.

For logging software I’m using RumLogNG which is a free logging program for Mac. You can install it now and test the CAT control functionality. Here are the CAT settings for RumLogNG that I used:

While you’re in the settings for RumLogNG, click on the UDP tab and setup the UDP server the WSJT-X will use for CAT control. Here’s are the settings:

Now is a good time to create a new log file in RumLogNG, otherwise contacts from WSJT-X won’t log due to not having a log file.

WSJT-X can be downloaded here. I’m not going to go into all the configuration options for this program, it’s heavily documented on the Internet. To configured communication between RumLogNG and WSJT-X I used the following settings on the Radio tab:

To pass the QSO’s to the log, set the following setting the UDP Server section on the Reporting tab:

This completes the software configuration. The final part took me the longest which is getting the audio into WSJT-X. It took me the longest mostly due to being cheap. I first tried using an old PS/2 keyboard cable to plug into the data port of the FT-891. These cables only have 4 of the pins wired and of course missing the ones we want. The official CT-39A cable is almost $20 but it’s the same connector used on old PS/2 mouse and keyboards. I purchased a 10ft PS/2 extensions cable (male to male, in case I screwed up I’d have 2) and cut it in half. The extension cables have all 6 pins. I cut in half an 3.5mm AUX audio cable and connected the red cable of one to the DATA Out Receive Audio, and the red of the other to the DATA In Transmit Audio and both the white and shield cables to the GND of the PS/2 connector. Here’s the pinout of the male plug:

The female pinout can be found on page 64 of the FT-891 Advance Manual.

Here’s what my cable looked like, pluged into a USB-C Sound Card adapter for Mac:

In the Audio section of WSJT-X configure the send and recieve to USB Audio. I’ve seen some mention of going into Applications->Utilities and Audio MIDI Setup to configure the USB Audio to use 48kHz but mine was already set to that by default. Another post had mentioned setting it to 41000Hz if you had issues but I didn’t need to do that.

The point of this project was to be able to get quick contacts from my car for Parks on the Air. I’m going to be hitting quite a few parks soon and for the less interesting ones I figured I would just work FT8 from the car and then move on to the next. For power I have wired some anderson power pole connectors to the power terminals I have setup for my car audio system. I bought a bunch of ham stick antennas at the club swap meet and then ordered a magmount for my car and adjusted the 20m hamstick to resonance at 14.074MHz. I could only get 1.9 SWR but that was good enough. I tested this setup from my driveway and found it works pretty well.

I’m heading out on a Parks on the Air adventure soon and I’ll be posting on how this all works in practice.