Yaesu FT-710

Best for: Yaesu FT-710 (AESS / Field) — CAT, audio, and remote CW all over the radio’s single USB cable.

The FT-710 exposes two COM ports and a USB sound card over one USB cable. The Enhanced COM port is the one that carries CAT — use it for the rig connection. For general connection-method background, see Radio Setup.

Connection settings

1. Windows: install Yaesu’s FT-710 USB driver from their website (the plain USB driver — the separate “virtual sound driver” is not needed). Linux: no driver needed; the radio is plug-and-play.
2. Add a new rig → select Serial CAT (Kenwood) (details) — not Hamlib.
3. Choose the radio’s Enhanced COM port.
4. Set the baud rate to 38400 (matching the radio’s CAT rate).
5. Check Disable DTR/RTS on connect.
6. Click Test Connection, then Save.

Note: Use Serial CAT rather than Other Rig (Hamlib) for this radio. Under Hamlib, power-on and several rig-control buttons are unreliable on the FT-710. Over Serial CAT, remote power on/off works — including from the ECHOCAT power button.

Tip: Power the radio on before opening the rig settings screen — with the radio off, the audio device dropdowns stay empty.

Radio menu settings

Audio & digital modes

• In Windows Sound settings, set the radio’s USB audio device to 16 bit, 44100 Hz (CD Quality). The Windows default of 48000 Hz breaks TX audio on this radio.
• In POTACAT’s rig settings, set RX Audio In and TX Audio Out both to the radio’s USB audio codec. A common failure is TX audio routed to the PC speakers instead of the rig.
• SSB-over-DATA (Settings → ECHOCAT) works well on the FT-710. The radio flipping to DATA-U in red while you key from the phone is normal and expected — see SSB over DATA.
• If you use SSB-over-DATA, also change the radio’s DATA MODE setting from PSK to OTHERS — otherwise TX lands off the dial frequency in DATA mode.

CW keying

The FT-710’s CAT KY command is unreliable for CW text — it raises the carrier but doesn’t reliably key Morse. POTACAT instead keys this radio per-element using DTR on the radio’s second (CAT-2) COM port:

1. In POTACAT Settings, set CW Key Port to the radio’s second COM port (e.g. COM4 if CAT is on COM3, or /dev/ttyUSB1 on Linux).
2. On the radio, set OPERATION SETTING → CAT/LINEAR/TUNER → USB KEYING (CW) to DTR.
3. Turn break-in on: FUNC → RADIO SETTING → CW → CW BK-IN = ON or SEMI.

Without a CW Key Port configured, POTACAT falls back to the KY command — expect missed or garbled sending.

Warning: On Linux, some cdc_acm USB-serial drivers can’t control the DTR pin (Operation not supported in the log). The pin sticks high and the radio can key continuously while POTACAT runs. POTACAT falls back to a Python/pyserial helper for CW text (install python3 and pyserial), but that only handles word-at-a-time text — real-time paddle keying needs a cheap FTDI/CH340 USB-serial adapter wired to the rear KEY jack, set as the CW Key Port. If the rig gets stuck keyed, set USB KEYING (CW) = OFF on the radio.

Known quirks

• ATU: remote tune via CAT is not supported by Yaesu’s firmware on this radio — no CAT command starts a tune cycle. Use the front-panel TUNE button.
• SWR bar: POTACAT’s SWR bar over-reads on Yaesu rigs — trust the radio’s own meter.
• Some users report that a few panel controls (ATT, preamp, COMP, NR, ANF, VOX) don’t respond from POTACAT even though the power slider, VFO knob, and power on/off work fine.