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FT-897D + SCU-17: AFSK modes with CAT control in Debian linux

How to get the FT-897D and SCU-17 set up to work AFSK modes with CAT control in Debian Linux.

Table of Contents:

  1. Preface
  2. Radio Menu Settings
  3. Flrig Settings
  4. Radio Operation Settings
  5. Operating System Settings
  6. SCU-17 Settings
  7. Software Modem Settings
  8. Troubleshooting

Preface:

So, you want to get your FT-897D working on an AFSK mode do you? Well this is how I chose to do it. I wouldn’t be surprised if this works well for other Yaesu radios of the era. This may even be very similar to the FT-991A barring the specific radio menu numbers. I’m using Debian 11 stable. I actually had a much worse time with the testing packages. They are definitely not ready for prime-time as of this writing

What you’ll need to follow along:

I had a bad time, like others on the net, trying to get their FT-8xx’s to play nice with the hamlib package shipped with most Debian based distributions. By the time you read this, the problem may have been fixed, so it is worth trying out. As of this post however, it’s not working. I will update this information as I periodically test the hamlib package.

Flrig uses hamlib under-the-hood but they bake a modified version of the library into their source so that it is standalone. Whatever they are doing is working to get the FT-897D and SCU-17 playing well together in Linux. Both flrig and fldigi have specific checkboxes labeled ‘SCU-17’ in their configuration menus so there has been some attention paid to specifically get the unit to work satisfactorily with the software.

First, you really need the manual close by unless you’ve got a handle on all of the menu settings. The FT-897D is the poster child for wacky menu driven radios. Connect up the radio to the SCU-17 using the CAT and DATA ports. Be careful not to confuse the two ports. Cable labels are your friend here. The delicate pins on these connectors are easily bent and they are not the same pin configuration. The SCU-17 manual has diagrams if you’re unsure of how to connect it up.

Radio Menu Settings:

  • Hold the [F] key for a second to enter menu mode.
  • Menu Mode: No-001 [EXT Menu] = ON
    • This needs to be enabled first before the other menu items become available. Hold the [F] key to save the setting.
  • Menu Mode: No-019 [CAT RATE] = 38400
  • Menu Mode: No-020 [CAT/LIN/TUN] = CAT
  • Menu Mode: No-037 [DIG GAIN] = 50
  • Menu Mode: No-037 [DIG MODE] = USER-U
  • Menu Mode: No-080 [SQL/RF Gain] = RF Gain
  • Save Menu Settings

Flrig Settings:

  • In the configuration settings, select the FT-897D under the radio model listing.
  • Set the baud ‘CAT’ rate to 38400
  • Exit the configuration menu
  • Click “Connect”

Radio Operation Settings:

  • Change mode to ‘Digi’
    • Use the mode arrow keys
  • To access Multi Function Row (MFR) settings:
    • Press the F key
    • Rotate the MEM/VFO knob
  • MFR’x’ settings:
    • ‘i’ – Press the [A] key under [MTR] so that [ALC] is displayed beside it over the [B] key.
    • ‘l’ – Disable AGC
    • ‘p’ – Disable all DSP
  • While tuned to a frequency with the desired signal, manually dial in the RF Gain using the RF Gain/Squelch ring to make sure you aren’t overdriving the incoming signals. The sweet spot tends to be between 11 and 1 o’clock.

Operating System Settings:

  • Use alsamixer to set both input and output to 100%.
  • Set the PC’s default sound card to the internal sound card and not the SCU-17.
    • Doing this prevents you from being the idiot sending your GridTracker text-to-speech alerts over your FT-8 transmission. 🤦🏽‍♂️

SCU-17 Settings:

You’ll need to look up what input levels your software wants but you’ll adjust the RX knob to achieve that. For output operation, with the TX knob rotated all the way to the left and the RF Power set to 5 watts, send a test transmission while viewing the ALC meter. The manual specifies that for AFSK modes your audio level should be around 7-8 on the meter’s scale. Slowly bring up the TX knob while transmitting until the ALC reads 7-8ish. WSJT-X has a ‘Tune’ button that’s great for setting the output level.

Software Modem Settings:

To use this setup, your chosen software modem has to work with flrig. Between fldigi and WSJT-X, nearly all the popular digital modes are covered. Just set the CAT control radio model in the other software to flrig. You’ll also want to set the PTT control to CAT where applicable and the audio being received set as coming from the back of the radio.

Troubleshooting:

The FT-897D has not been entirely without its problems where CAT control is concerned. I have noticed the occasional hang up. The radio will become unresponsive to software control and flrig cannot reconnect to the radio. This appears to be a radio/software issue and not the SCU-17. When the radio gets into this state, no other CAT interface I have works either. The way I fix it is to:

  1. Close flrig
  2. Shut off the radio
  3. Unplug the USB interface
  4. Turn the radio back on
  5. Plug in the usb interface
  6. Start flrig

Note: I think it may actually be a known hamlib bug getting the radio into this state. I came across a brief mention of a bug that has been supposedly fixed upstream regarding FT8xx radios. I wouldn’t be surprised to find that this cache related timeout bug crept back in somehow.