G90 CAT Control and Digital Modes

CAT Control Your Xiegu G90 with Your PC and Start Operating in Digital Modes

Table of Content

• 1. Disclaimer
• 2. Intention of this document
• 3. Explanations on vocabulary
  • IO-port
  • CAT
  • CE-19
  • OpenSource
• 4. Connect your Xiegu G90 to your PC
  • The blue USB-cable
  • The 8-pin miniDIN ACC cable
    • PTT (1)
    • BAND (2)
    • AF-IN (3)
    • AF-OUT (4)
    • ALC (5)
    • DATA OUT (6)
    • GND (7)
    • +8V (8)
• The CE-19 interface
• 5. CAT control
  • Select Line input
  • Set AUX-IN volume
  • Set AUX-OUT volume
  • PTT method
  • Disable AGC
  • HF power and ALC
• 6. CI-V implementation
• 7. Details on some of the possible digital data modes
  • FT8
  • JS8
  • WSJT
• 8. Software for CAT control and digital data modes
  • Flrig
  • FLdigi
  • Ham Radio Deluxe
  • WSJT-X
  • Dimension 4
  • GridTracker

1. Disclaimer

The technical details within this document have been put together by our engineers. Although we tried to be as accurate as possible, we do not guarantee this document to be free of errors. Use it at your own risk. Radioddity may not be held responsible for any damages caused by the use of the contained information.

We do not recommend creating required cables yourself but advise purchasing them at www.radioddity.com, via our Amazon-pages, or at your local dealer.

Windows™, Linux™, and OS X™ are the properties of their respective owners. Should any trademark attribution be missing, mistaken, or erroneous, please contact us as soon as possible for rectification.

2. Intention of this document

This document cannot replace the existing documentation for your Xiegu G-90 HF transceiver bought at Radioddity. It is intended to provide additional information and help in connecting and operating your Xiegu G90 with the help of your PC.

3. Explanations on vocabulary

When connecting your PC to your Xiegu G90, you will sooner or later encounter several abbreviations and special words. Let's explain some of them in more detail:

IO-port

IO-port is an abbreviation for the input and output port of a device.

CAT

A device used to control your radio is called a Computer Aided Transceiver.

CE-19

The Xiegu CE-19 is an add-on device for your Xiegu G90 transceiver that connects via the ACC-port to your Xiegu G90. It has separate ports for PTT and AF (Audio). Furthermore, it has a miniDIN-6 socket required to operate a Xiegu XPA-125 amplifier.

OpenSource

According to Wikipedia, ‘Open-source software (OSS) is a type of computer software where its source code is released under a license in which the copyright holder grants users the rights to use, study, change, and distribute the software to anyone and for any purpose. Open-source software may be developed in a collaborative public manner'.

Although such software is free for the user, it is often even more powerful than expensive licensed software. Therefore, we encourage all users of OpenSource Software to honor their originators by either contributing to the development of the software or by other means ('cup of coffee', contribution to some social organization, or other ways). Examples for OpenSource software for HAM use may be found at: sourceforge.net/directory/communications/hamradio

4. Connect your Xiegu G90 to your PC

Depending on the type of computer aided transceiver control, you need certain connections or even additional interfaces.

The blue USB-cable

Together with the Xiegu G90 HF transceiver you bought at Radioddity, you quite likely also got a so-called ‘XIEGU radio universal data cable', also known as 'the blue USB-cable'. That cable has a total length of about 90cm and comes with a 3.5mm Stereo-jack on one side and a blue USB Type A plug on its other side.

Within the blue USB plug, a FTDI-compatible FT232BL chip converts the USB-signals into normal serial-port signals. Only TX-Data, RX-Data, and Ground are connected to the Xiegu G90, which means there is no hardware-based handshake possible for the data transfer, only software-based handshake.

ℹ️ Note: The very first Xiegu G90s were delivered with a black USB-cable. That black USB-cable is not based on a FTDI-chip but on a Prolific chip and therefore requires a different device driver. Everything else stated about the blue USB-cable applies to the black one as well.

Cable Connections (USB)

Hint: In order to prevent unwanted interference between the PC and the Xiegu G90 transceiver via the blue USB cable, we advise you to add additional EMC magnetic rings or clip-on ferrite filters close to both ends of the cable.

Due to the fact that the USB2Serial-converter circuit is not an original FTDI but a compatible version, it might be required for the cable to be properly identified by your PC's device manager to install an older FTDI-driver version. Within the device manager of your Windows™-based PC, you should find a serial port of type FTDI. You may download the appropriate Windows™ driver for the FT232BL chip directly from the FTDI website at ftdichip.com/drivers/d2xx-drivers/. Make sure you use version 2.08.24!

With the blue USB-cable, you can accomplish the following tasks:

• Update of base-unit as well as update of display-unit
• Set parameters of your Xiegu G90 transceiver (except pushing the PTT)

ℹ️ Note: Audio signals will not be transmitted via the blue USB-cable.

*¹ Whenever updating your Xiegu G90 HF transceiver, make sure that both, the base-unit as well as the display-unit, get the matching version numbers (normally both the very same).

ℹ️ Note: For updating the firmware of a Xiegu G90, the speed to be used is 115000 bps, whereas for CAT control the speed to be used is 19200 bps.

The 8-pin miniDIN ACC cable

On the backside of your Xiegu G90, there is an 8-pin miniDIN socket for connecting accessories, named ACC.

The pinout of this miniDIN-8 is shown below:

Pinout Diagram Description: The diagram shows an 8-pin miniDIN connector labeled ACC. Pins are numbered 1 through 8. Pin 1 is PTT, Pin 2 is BAND, Pin 3 is AF-IN, Pin 4 is AF-OUT, Pin 5 is ALC, Pin 6 is DATA OUT, Pin 7 is GND, and Pin 8 is +8V.

The purpose of each signal is as follows:

PTT (1)

Pin 1 of the miniDIN-8 socket is input as well as output. Whenever the transceiver is in TX mode, pin 1 of the miniDIN-8 will be 'L'. If connected to ground via this pin, the transceiver will switch to Transmit-Mode. If not connected to ground, the transceiver will be in Receive-Mode.

ℹ️ Note: We will use VOX-control. More on that in a later chapter.

BAND (2)

At pin 2 of the miniDIN-8 socket, the G90's ACC port provides a band data voltage output for each band. The band data can control peripherals to automatically switch the band or share the band information with other devices (e.g., XPA-125B amp). The stepping value between each band is 230mV.

AF-IN (3)

As mentioned, audio signals are not transmitted via the blue USB cable. For the audio signal to be transmitted, you need this external audio frequency input interface to pin 3 of the miniDIN-8 socket. When the Xiegu G90 is used for data communication with a computer or an external modem, the correct input signal options need to be selected.

1. Input the external audio signal to AF-IN of the ACC port.
2. Enter the second option of the INPUT button [FUNC+POW+POW] to select 'LINE' instead of 'MIC'.
3. In the system menu, select: AUX IN VOLUM to set the appropriate input volume (as described below).

When the AF-IN pin of the ACC interface is used for line input audio, set the appropriate input volume in the "AUX IN Volume" option in the system menu. Set it at a mid-level value first. When using digital communications and the ACC port is used for audio input, the audio level coming in should be capable of 200mV.

Then, watch TX power output (while keyed) and adjust your incoming audio from the PC (using the PC's sound card output volume level control). You want to set the radio at 20W output in digital modes and lower the audio level coming from the PC such that the average power level on TX is around 10W. Digital modes can have long key-down times and the radio will heat up more. Plus, digital modes require a very clean signal, which can be achieved with a lower audio drive level.

With a good antenna, 10W average output is easily sufficient for most digital mode communications, as they are very efficient. Keep a check on the temperature of the radio when you operate digital modes (and in general). Your ambient temperature might be 13°C (55°F) or 40°C (105°F), which has a great impact on heat build-up. If the radio becomes very hot, you'll need to reduce power or give it a cool-down rest. The radio's transmit section is very conservatively designed, but any radio can be over-heated under certain challenging operating conditions.

Hint: Radioddity offers a special ‘G90-H1 Holder Cooling Fan Bracket for Xiegu G90'. Besides its cooling functionality, this stand also places the Xiegu G90 into a better reading position on your desk.

AF-OUT (4)

What AF-IN is for the transmitted audio input signal, AF-Out on pin 4 of the miniDIN-8 socket is for the received audio output signal, which is called 'AUXOUT' within the G90 firmware. In the system menu, select: ‘AUXOUT Volum' to set the appropriate output volume (this will be covered later).

The software you use for CAT-control often provides an audio-meter showing best input levels (as seen from the PC).

When using digital communications and the ACC AF-OUT port is used for PC-side TX audio input, the input audio drive level of the PC should be capable of handling 200mV.

In the system menu, the following two settings are the ones to be adjusted for data communications:

For data communications, the volume output level (sound card output) of the PC is to be adjusted according to the 'AUXIN Volum' (which becomes your TX audio).

The volume of the input to the computer (normally the mic input) also needs to be adjusted according to the 'AUXOUT Volum' (received audio going to the PC).

These PC settings are normally found within ‘Sound devices'. It is best to set the radio to mid-level settings and then adjust the PC's levels for proper operation. Fine tuning from that point can be done with the G90's menu settings.

ALC (5)

The input signal on pin 5 of the miniDIN-8 socket may vary between 0....3.3V. The higher the ALC voltage is, the higher the power.

DATA OUT (6)

Pin 6 of the miniDIN-8 socket is connected to the tip and ring of a 3.5mm TRS jack on the Xiegu CE-19, labeled DATA CON but not routed within the G90.

GND (7)

Normal power supply ground is connected to Pin 7 of the miniDIN-8 socket.

+8V (8)

Pin 8 of the miniDIN-8 socket drives +8V DC for powering the CE-19 interface. The maximum current available at this pin is 50mA. This pin is not intended to connect any electronics.

The CE-19 interface

In order to make the required audio connections between the G90 and your PC, you need the Xiegu CE-19 interface. Using the miniDIN-8 cable supplied with the Xiegu CE-19, the Xiegu G90 is connected via its ACC port to the miniDIN8-socket of the Xiegu CE-19 interface.

ℹ️ Note: The miniDIN6-socket also found on the Xiegu CE-19 is used for connecting a Xiegu XPA-125B amplifier. Be careful not to mix the two miniDIN-sockets up, as it would result in bent pins of the miniDIN plugs.

The CE-19 comes with 3 premade cables. On one side of these cables, there is a green 3.5mm TRS plug, and the other side has colored open ends.

The pin assignment of these cables is as follows:

Furthermore, you will also find three separate black 3.5mm TRS plugs.

PCs have a speaker output and a line or mic input. You will need at least two of these supplied cables to make a proper wiring between your PC and the Xiegu CE-19.

Wiring with Green and Black Plug Cables

To connect your PC to the Xiegu CE-19 interface using two of the green plug cables and one black plug, you need to wire the cables as follows:

Wiring with Green Plug Cables

To connect your PC to the Xiegu CE-19 interface using two of the green plug cables for the PC-side and the remaining green plug cable for the Xiegu CE-19 side, you need to wire the cables as follows:

Hint: The same advice that applies for the USB cable also applies for any other cable. In order to eliminate RF signal interference between the PC and the Xiegu G90 transceiver, we advise you to add additional EMC magnetic rings or clip-on ferrite filters close to both ends of the audio cables.

5. CAT control

For CAT control, you need to connect the 3.5mm stereo-jack of the blue USB cable to the IO-port of the display-unit (17), as the IO-port found at the back of your Xiegu G90 does not support CAT control.

ℹ️ Note: If you use the GSOC for operating your Xiegu G90 base-unit, CAT control is not supported as the GSOC does not have the IO-port required for CAT control.

Select Line input

Select Line input instead of Microphone by: [FUNC] + [POW] + [POW] to select ‘LINE’ instead of ‘MIC’.

Set AUX-IN volume

Long-press [FUNC] to enter the configuration menu. Next press [NEXT], [NEXT], [NEXT], [NEXT] to advance to menu ‘5. AUXIN Volum’. Select a middle value of 7 or 8 as volume for AUX-IN (the allowed range is 0...15).

Set AUX-OUT volume

Hit [NEXT] once more to confirm the value and advance to the menu ‘6. AUX OUT Volum’ for setting the volume of the AUX-OUT signal of your Xiegu G90. Set it to the maximum value of 15. Confirm your selection with [SAVE], which will also exit the configuration menu.

PTT method

For operating the PTT, there are two possibilities: either via CAT control or by means of VOX. For automatic PTT by means of the audio out signal from your PC data-mode application, the VOX-function needs to be turned on. Hit [FUNC] + [VOL] and turn ‘VOX: ON’. For PTT by means of CAT control, the VOX-function needs to be turned off. Hit [FUNC], [VOL] and turn ‘VOX: OFF’.

Disable AGC

Next, disable AGC by hitting [AGC] until it states ‘AGC--’ on the Xiegu G90 display.

HF power and ALC

The output level from the computer to the radio should be adjusted so that the ALC value displayed on the screen ranges from 30 to 85. The lower the ALC, the better. You should set the radio a bit below its maximum of 20W output and adjust the PC's sound card output so that your ALC is within range.

Excessive high input signal level may overload the input amplifier, resulting in modulation signal distortion. With ALC correct, the TX power output reading may jump around rapidly under digital modulation, but average power levels will be in the correct range for a clean and effective signal. Digital modes are highly efficient and require much less TX power.

6. CI-V implementation

CI-V is an abbreviation for ‘Computer Interface, version V', first introduced by ICOM and used for CAT control since several decades. For the Xiegu G90, communication is carried out using serial communication between the G90 and the PC using the blue USB cable or a compatible cable.

Table 1 (part 1/2)

Table 1 (part 2/2)

Table 2-1

Table 2-2

Table 2-3

The Xiegu G90 responds to various addresses, such as 0x70 (Hex) (default), 0x88, and others.

7. Details on some of the possible digital data modes

As amateur radio operators like to experiment with new technology and adapt existing industry standards to the amateur radio world, new modes of radio operation pop up frequently. Let's take a closer look at some of those rather digital and data-focused modes that are currently quite popular.

FT8

FT8 was first publicly proposed in 2017 by Joe Taylor and named after the first letters of the surnames of its two developers, Steven Franke (K9AN) and Joe Taylor (K1JT), following the number 8 to indicate that eightfold frequency shift keying (MFSK8) is used. Since then, FT8 has become extremely popular on shortwave.

JS8

JS8 was derived from FT8 by Jordan Sherer (KN4CRD), resulting in its name Jordan Sherer 8 (eightfold frequency shift keying). In contrast to FT8, JS8 is mainly focused on the exchange of personal messages with the remote station, similar to the chat functionality of various instant messengers. The only software currently available that supports JS8 is called JS8Call (see js8call.com/ for more details).

WSJT

This Weak-signal transmission method was invented by Joe Taylor (K1JT). WSJT-X, as its current version, is a group of transmission protocols and free amateur radio software for communication using weak signals.

8. Software for CAT control and digital data modes

There are quite a few programs that can be used with your Xiegu G90. Some of them support the Xiegu G90 out of the box; others need to be set for IC-7100 or IC-756PRO, as those radios share most of their command set for CI-V CAT control with the Xiegu G90. The baud rate for CAT control of your Xiegu G90 should be set to 19200.

⚠️ Warning: As some CAT control programs poll the radio regularly, we advise generally to shut down the PC program and disconnect the blue USB cable from the Xiegu G90 after operating your G90 with the PC's help. This is to guarantee that the G90 does not boot up into firmware upgrade mode when it is turned on, and the polling of the PC software is interpreted as a keystroke for activating the update-function of the Xiegu G90.

Flrig

Flrig is mainly a CAT control program that can be used as a standalone solution or in combination with other programs such as fldigi or WSJT-X. Its main purpose is to control your Xiegu G90 via its IO-Port and the blue USB-cable connected between the G90 display-unit IO-port and your PC. Download from: sourceforge.net/projects/fldigi/files/flrig/

On first use of flrig, you need to configure it for use with your G90. To do so, select the 'Config' button in the top line of flrig, then move your mouse to 'Setup' and then to 'Transceiver'. Click to select that option.

Configuration Screenshot Description: The screenshot shows the Flrig setup window. Key elements include selecting 'Xiegu-G90' as the Rig, choosing the correct COM port (e.g., COM19), and setting the Baud rate to 19200. Other settings like Data Bits, Stop Bits, and Handshake are shown with default or recommended values. The 'Init' button is highlighted.

Now select ‘Xiegu-G90' as your device (1), select the proper COM-port that your blue USB-cable has been assigned to (2), and select a baud rate of 19200 (3). Leave the other parameters as shown in the screenshot. Next, click the ‘Init’ button (4). You will hear some noise from the relays inside the Xiegu G90. After that initialization sequence has finished, the status indicator (5) to the right of ‘Connected' should be colored green.

Your Xiegu G90 is now successfully connected, and you should see the same data displayed within flrig as on the display of your Xiegu G90.

Connected Screenshot Description: This screenshot shows the main Flrig interface after a successful connection. It displays frequency information (e.g., 28056.000 MHz), VFO status (vfoA, vfoB), and various controls for rig parameters like AGC, Pwr, ATT, Tune, and PTT.

Whenever the Xiegu G90 has not been implemented yet within a CAT control software you'd like to use, you may often select 'flrig' as the radio and use the software with flrig as the connection bridge to your Xiegu G90. This is a significant advantage of flrig.

FLdigi

Fast Light digital Modem Application, pronounced ‘F L digi' and abbreviated as FLdigi, is a cross-platform modem program that supports most of the peer-to-peer (live keyboard) digital modes used on the amateur radio bands. FLdigi requires a PC with a soundcard to route analog input and output via the sound card of your PC.

FLdigi Interface Screenshot Description: The screenshot shows the FLdigi interface with various modes listed (CW, DominoEX, MFSK, etc.). It displays frequency, callsign, and signal analysis windows. The path to configuration files is also visible.

FLdigi is available for a variety of platforms, such as Linux™, OS X™, Windows™, and FreeBSD™. Download from: www.w1hkj.com/ and sourceforge.net/projects/fldigi/.

Flrig and Fldigi are both OpenSource and continuously maintained by their developers W1HKJ & Associates. Both software packages are free. However, contributions are appreciated via gideons.org/.

Ham Radio Deluxe

Ham Radio Deluxe combines contact logging, rotor control, rig control, satellite tracking, and digital modes within one program suite. You can install a 30-day trial version to test it before buying. Download from: www.hamradiodeluxe.com/

WSJT-X

As mentioned, WSJT-X is a group of transmission protocols and free amateur radio software for communication using weak signals. To get it running as expected, a few settings are required. The following screenshots show examples of such.

WSJT-X Settings (General Tab) Screenshot Description: This screenshot shows the 'General' tab of WSJT-X settings. It allows configuration of Station Details (Callsign, Grid, IARU Region) and Display/Behavior options. Key settings include 'Tx watchdog' duration.

Within the 'General' tab, you set your callsign, grid locator, and IARU region. You may want to alter the ‘Tx watchdog' value, which defines the time at which WSJT-X gives up if it could not successfully manage a QSO.

WSJT-X Settings (Radio Tab) Screenshot Description: This screenshot shows the 'Radio' tab. It highlights the selection of the radio and recommends using 'flrig' for connecting to the Xiegu G90. CAT Control parameters like Network Server, Serial Port, Baud Rate, PTT Method, and Transmit Audio Source are configurable.

Within the 'Radio' tab, you select your radio. As already mentioned, we advise using 'flrig' for connecting to your Xiegu G90.

WSJT-X Settings (Audio Tab) Screenshot Description: This screenshot shows the 'Audio' tab, used to define the input and output signals from your PC's soundcard.

And not to forget the 'Audio' tab, which is used to define the input and output signals used from your PC.

If all is set up correctly, you should be able to decode digital signals. To make a QSO with another station, you have to manually enable TX by clicking the 'Enable TX' button. The function will automatically be deactivated as soon as your QSO has been completed or the TX watchdog has kicked in. More information at: physics.princeton.edu/pulsar/K1JT/wsjtx.html

Dimension 4

The successful operation of HF digital modes depends on exact TX timing, which is derived from the internal clock of your PC. Normally, a PC updates its internal clock once a day, which is not sufficient for the described digital modes. This is where Dimension 4 comes in. It is capable of more regular updates to the internal clock using SNTP (Simple Network Time Protocol) time sources from the internet.

Dimension 4 Interface Screenshot Description: The screenshot shows the Dimension 4 interface, allowing users to add and configure SNTP servers for time synchronization. It displays server addresses, protocols, and synchronization status. An example setup synchronizing with ptbtime2.ptb.de every 30 minutes is shown.

In the example above, it is set up to synchronize the internal PC clock against ptbtime2.ptb.de every 30 minutes. Download from: www.thinkman.com/dimension4/

GridTracker

Digital modes have a high focus on messages that are as short as possible. For example, FT8 does not transmit the city of the station but its locator. To get a better overview of the geographical location of stations, GridTracker is your way to go. Besides its excellent graphical output, it also automatically links to WSJT-X.

GridTracker Interface Screenshot Description: The screenshot shows the GridTracker map interface, displaying radio signal locations across Europe. It includes details like band, mode, callsign, distance, and time. The legend explains different markers.

GridTracker is available for a variety of platforms, such as various Linux™ distributions, OS X™, and Windows™. Download from: gridtracker.org/

Conclusion

We at Radioddity hope this document is of help for CAT control of your Xiegu G90 with your PC and for starting operations in digital modes!

Tutorials, Support, and More Can Be Found At:

• www.radioddity.com
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• www.youtube.com/c/Radioddityradio