RADIOMETEO · IZ6CLV

CAT/PTT Configuration

RADIOMETEO · RADIO LAB · CAT/PTT

Radio and computer, set up properly

CAT/PTT configuration: choose your radio and the software you use and get the settings to check on the radio and the computer, with profiles of the most popular models, a guide to digital-mode software and fixes for the most common problems.

Radios included: the models most used by radio amateurs — Icom IC-7300, IC-705, IC-9700, IC-7610, IC-7100 · Yaesu FT-991A, FT-710, FTDX10, FTDX101, FT-891 · Kenwood TS-590SG, TS-890S, TS-2000 · Elecraft K4, K3S, KX3 · Xiegu X6100, G90 · FlexRadio 6000/8000. The list will be extended.

Software included: WSJT-X, JTDX, JS8Call, fldigi with flrig, VARA HF with Winlink Express and VarAC, Ham Radio Deluxe with DM780, MMSSTV, FreeDV, N1MM Logger+ and Log4OM.

Guided CAT/PTT configuration
iCAT is computer control of the radio (frequency, mode, sometimes transmit). PTT is the command that keys the radio: it can go through CAT, an RTS/DTR line of the serial port, or VOX.

Choose brand, model and software to get the ordered list of settings on the radio and in the software. Values come from the manuals and documentation listed in the sources; where a value is not confirmed you will see “check the manual”.

Choose brand and model: the settings appear right here.

Radio profiles

Connection and main settings for the CAT/PTT configuration of each model. Menu items are shown as they appear on the radio.

Icom

IC-7300 · IC-705 · IC-9700 · IC-7610 · IC-7100

Yaesu

FT-991A · FT-710 · FTDX10 · FTDX101D / MP · FT-891
Yaesu FT-991A

Connection: One USB cable with two virtual COM ports: “Enhanced” for CAT, “Standard” for PTT and CW via RTS/DTR; audio through the built-in USB sound card.

Settings on the radio
CAT speed031 CAT RATE: 38400 bps
CAT time-outCAT TOT: 10 ms
CAT RTSCAT RTS: DISABLE
Data mode062 DATA MODE: OTHERS
Data input070 DATA IN SELECT: REAR
Data PTT071 DATA PTT SELECT: DAKY
Data port072 DATA PORT SELECT: USB

Many Yaesu transceivers require 2 stop bits: if the CAT test fails, check this setting.

Sources: FreeDV — Yaesu FT-991A · DXLab — Yaesu SCU-17 · MacLoggerDX — Radio specific settings

Yaesu FT-710

Connection: One USB type B cable for CAT, audio in and out and transmit control.

Settings on the radio
CAT speedCAT-1 RATE 38400 bps
CAT time-outCAT-1 TIME OUT TIMER 10 ms
PC KeyingPC KEYING: OFF

Many Yaesu transceivers require 2 stop bits: if the CAT test fails, check this setting.

Sources: Yaesu UK — FT-710 AESS · MacLoggerDX — Radio specific settings

Yaesu FTDX10

Connection: One USB cable with two virtual COM ports: “Enhanced” for CAT, “Standard” for PTT and CW via RTS/DTR; audio through the built-in USB sound card.

Settings on the radio
CAT speedCAT RATE 38400 bps
CAT RTSCAT RTS: OFF
PC Keying (only if you use RTS for PTT)PC KEYING: RTS

Many Yaesu transceivers require 2 stop bits: if the CAT test fails, check this setting.

Sources: DXLab — Yaesu SCU-17 · MacLoggerDX — Radio specific settings

Yaesu FTDX101D / MP

Connection: One USB cable with two virtual COM ports: “Enhanced” for CAT, “Standard” for PTT and CW via RTS/DTR; audio through the built-in USB sound card.

Settings on the radio
CAT speedCAT RATE 38400 bps
CAT RTSCAT RTS: OFF
PC Keying (only if you use RTS for PTT)PC KEYING: RTS

Many Yaesu transceivers require 2 stop bits: if the CAT test fails, check this setting.

Sources: DXLab — Yaesu SCU-17 · MacLoggerDX — Radio specific settings

Yaesu FT-891

Connection: For digital modes the Yaesu SCU-17 interface is used: “Enhanced” port for CAT, “Standard” port for PTT via RTS and a USB sound card inside the interface.

Settings on the radio
CAT speedcheck the manual

Many Yaesu transceivers require 2 stop bits: if the CAT test fails, check this setting.

Sources: WiMo — Yaesu SCU-17 · DXLab — Yaesu SCU-17

Kenwood

TS-590SG · TS-890S · TS-2000
Kenwood TS-590SG

Connection: One USB cable: virtual COM port for CAT and “USB Audio CODEC” sound card. The Kenwood driver is required.

Settings on the radio
USB port speed068 USB PORT BAUD RATE: 115200
Data audio source (menu)069: USB
USB audio input level (menu)071
USB audio output level (menu)072

Install the Kenwood driver; on Windows 7 and later connect the radio after installing it.

Sources: DXLab — Connecting Kenwood TS-590/890/990 via USB · MacLoggerDX — Radio specific settings

Kenwood TS-890S

Connection: One USB cable: virtual COM port for CAT and “USB Audio CODEC” sound card. The Kenwood driver is required.

Settings on the radio
USB port speedcheck the manual
USB audio input level (menu)7-07
USB audio output level (menu)7-08

Install the Kenwood driver; on Windows 7 and later connect the radio after installing it.

Sources: DXLab — Connecting Kenwood TS-590/890/990 via USB

Kenwood TS-2000

Connection: RS-232 serial port for CAT; audio goes through an external audio interface.

Settings on the radio
Control port speed056 COM PORT: = software

After changing the speed, switch the radio off and on again.

Sources: MacLoggerDX — Radio specific settings

Elecraft

K4 · K3S / K3 + KIO3B · KX3
Elecraft K4

Connection: USB type B “PC” port: two virtual COM ports (USB-PC1, USB-PC2) for control and a digital sound card (LINE IN and LINE OUT). Ethernet for remote control.

Settings on the radio
Control port speedcheck the manual

Elecraft recommends Ethernet for software updates and remote control.

Sources: Elecraft — K4 Operating Manual

Elecraft K3S / K3 + KIO3B

Connection: With the KIO3B board (fitted in the K3S): direct USB connection and built-in sound card for Line In and Line Out.

Settings on the radio
Control port speedcheck the manual

Sources: Elecraft — KIO3B FAQ (K3S)

Elecraft KX3

Connection: Elecraft KXUSB cable: creates a virtual COM port for radio control. For digital-mode audio check the manual.

Settings on the radio
Control port speedcheck the manual

Sources: Elecraft — KXUSB

Xiegu

X6100 · G90
Xiegu G90

Connection: Icom CI-V compatible protocol. Cables and audio: check the manual for your model.

Settings on the radio
CI-V addresscheck the manual
CI-V speed (USB)19200
CI-V Echocheck the manual

The sources consulted give different CI-V addresses (88h and A4h): read the one set in your radio and use the same in the software.

Sources: Hamlib — Icom/Xiegu source (CI-V addresses) · MacLoggerDX — Radio specific settings

FlexRadio

FLEX-6000 / 8000
FlexRadio FLEX-6000 / 8000

Connection: All over the network: SmartSDR CAT on a TCP port for control and DAX audio channels instead of a sound card.

Settings on the radio
SmartSDR CATSmartSDR CAT: TCP 60000
SliceDIGU · DAX 1
DAXDAX TX gain ≈ 45 · RX 1 ≈ 35

Official FlexRadio procedure for SmartSDR up to version 4.1.5.

Sources: FlexRadio — WSJT-X, FLEX 6000/8000

Digital-mode software and loggers

Where CAT, PTT and audio are set in the most used programs, and what to check.

WSJT-X

File → Settings → Radio and Audio. Rig, Serial Port, Baud Rate, Handshake, PTT Method (VOX, CAT, DTR, RTS), Mode (None, USB, Data/Pkt), Split (None, Rig, Fake It), Test CAT and Test PTT buttons. Audio at 48000 Hz and 16 bit; clock within ±1 s.

WSJT-X User Guide ↗

JTDX

Derived from WSJT-X (FT8, FT4, JT65, JT9, WSPR) and follows its radio and audio settings layout. The old jtdx.tech website is no longer active (checked on 18/10/2026): download the program only from trusted sources, such as Linux distribution repositories.

Debian — JTDX manual page ↗

JS8Call

Built on the WSJT-X/FT8 engine: radio and audio settings follow the same principles as WSJT-X.

JS8Call ↗

N1MM Logger+ · Log4OM

Contest and general loggers. The radio’s COM port can be opened by one program only: to use them with WSJT-X, control must be shared. Menus and options in the official documentation.

N1MM Logger+ Docs ↗
Log4OM ↗

Common problems and fixes

The cases that come up most often in CAT/PTT configuration, when connecting radio and computer, with the checks to make in order.

Test CAT red: the radio does not respond

Check in order: the right COM port (on Yaesu radios with two ports it is the “Enhanced” one); speed, stop bits and handshake matching the radio; on Icom radios the same CI-V address and a fixed CI-V speed, not “Auto”; the radio driver installed.

COM port busy or “access denied”

Another program (logger, flrig, manufacturer software) already has the port open. Close it or let only one program control the radio and share it.

PTT does not switch or the radio stays in transmit

Check the PTT method: CAT, or RTS/DTR on the right port (on Yaesu the “Standard” one). On some Yaesu radios CAT RTS must be off; in WSJT-X also check “Force Control Lines”.

It keys up but there is no output power

The software sends audio to the wrong device, or the radio takes audio from the microphone instead of the data/USB port: check the data audio source in the radio menu.

Distorted or wide signal

Audio level too high and ALC active. With Tune, lower the Pwr slider until output drops slightly; the tone must be clean, with no clicks.

FT8 decodes nobody

The computer clock is out of tolerance: it must be within ±1 s of UTC.

USB disconnects or PTT goes wild while transmitting

Often RF getting into the cables: ferrites and common-mode chokes on the coax and on USB and audio cables. Also turn off Windows USB power saving. Go to QRM Troubleshooting →

Sources: Hamlib — Icom/Xiegu source (CI-V addresses), DXLab — Icom transceiver control, DXLab — Connecting an Icom transceiver, MacLoggerDX — Radio specific settings, FreeDV — Yaesu FT-991A, DXLab — Yaesu SCU-17, Yaesu UK — FT-710 AESS, WiMo — Yaesu SCU-17, DXLab — Connecting Kenwood TS-590/890/990 via USB, Elecraft — K4 Operating Manual, Elecraft — KIO3B FAQ (K3S), Elecraft — KXUSB, FlexRadio — WSJT-X, FLEX 6000/8000, WSJT-X User Guide, Fldigi Users Manual, openSUSE — Fldigi, JS8Call, N1MM Logger+ Docs, Log4OM, Debian — JTDX manual page, flrig — Initial Setup, fldigi — Xcvr Control Configuration, fldigi — Audio Sound Card, VARA (EA5HVK) — download / docs, VarAC — Quick start guide, FlexRadio — Winlink Express, VarAC, Ham Radio Deluxe — Making Your First Radio Connection, Ham Radio Deluxe — DM-780 with built-in soundcard, Ham Radio Deluxe — WSJT-X with HRD, FlexRadio — MMSSTV configuration, FreeDV — Getting started, FreeDV — User Manual. Sources consulted on 18 October 2026. Links open on the publisher’s website.

Articles on CAT, PTT and digital modes

RadioMeteo articles about interfaces, CAT, PTT and digital-mode software appear here automatically when they are published.