FTDX-1200 and SCU-17 a very useful document! supplied to me from HRD Support.. maybe it will save your hair!!!!


  • The SCU-17 interface unit may be used for CAT control of a Yaesu transceiver with a computer via a USB connection and for communications using SSTV, RTTY and PSK digital modes.
  • Note: YAESU does not produce CAT, SSTV, RTTY and PSK System operating software, due to the wide variety of personal computers, operating systems, and applications in use today.
  • The SCU-17 provides CAT communication through the USB terminal when a PC does not have an RS-232C connection.
  • The SCU-17 is equipped with a USB audio system device, so the TX and RX audio system signals are accessible to the SCU-17 through the USB cable. Therefore, the supplied USB cable is the only connection needed between the SCU-17 and PC.
  • The SCU-17 is equipped with a two-channel USB serial device and enables the various transmission modes and the CAT communication simultaneously.
  • The SCU-17 operates from the USB bus power; you do not need to prepare an external power supply.
  • For RF isolation, the SCU-17 is designed with photo relays for the PTT/FSK terminals; AF transformers are used in the AUDIO IN/OUT lines to provide excellent ground isolation.
  • The SCU-17 is equipped with the TX and RX audio controls on the front panel for convenient level adjustment.
  • LED indicators on the SCU-17 front panel monitor the PTT and FSK control the operating conditions may be quickly confirmed.
  • When using the SCU-17 to perform TX control, the transceiver may switch to transmit mode when the computer is started.
  • Virtual COM port driver Installation
  • SCU-17 drivers scu17 The Silicon labs drivers for the FT-991 FT-DX 3000 are the same as the SCU-17.
  • Ft-891 Advanced user manual ft-891_advance_manual
  • Destination Document destination_sheet_e00005035
  • ARS Document ars_setting_sheet_e00005036
  • Silicon Labs USB Drivers (FT-991/991A, FT-DX3000 Drivers) cp210x_windows_drivers-1
  • Install the virtual COM port driver on the personal computer before using the SCU-17 USB interface unit.
  • Please see the USB Driver (Virtual COM Port Driver) on the Yaesu Website for details refer to (http://www.yaesu.com/) in the FTDX12OO product files section.
  • Note: Do not connect the USB cable and SCU-17 to your personal computer until after the “virtual COM port driver” installation is completed, because an incorrect driver may be installed.
  • For assistance with the software port configuration, refer to “How to Confirm the Installation, and the COM Port Number” in the “Virtual COM port Driver Installation Manual”
  • For information on port configuration for commercial and free computer software, refer to the manual for the software being used.
  • When using the USB cable to supply TX and RX audio signals, set the
    Sound Card (input and output) settings to “USB Audio CODEC”
  • When using the USB cable for computer TX control, the transceiver may
    switch to transmit mode when the computer is started, etc.
  • YAESU does not provide technical support for the use or operation of commercial or free computer software.

PTT/FSK Control and Attenuator Setting

The PTT/FSK setting maybe changed and the audio attenuation maybe enabled by changing the configuration of an internal switch and jumper.

  1. Disconnect all the cables from the SCU-17
  2. Referring to figure 1, remove the 4 screws attaching the top case, then remove the top case.
  3. Locate the switch (S1001) and jumper (J1006)
  • S1001: PTT/FSK control setting
  • J1006: Attenuator setting to the audio IN/OUT Jack.
  1. Replace the top case in reverse order of step 2 above.
  2. Reconnect the cables to the SCU-17.



Typical connection of a radio