The Xiegu G90 is a great little affordable radio which has digital capabilities. While Xiegu (CEE-eh Goo, not Zy-Goo for you non-Mandarin speakers) does supply a break out module, the CE-19 for connecting to a soundcard with digital modes, many hams prefer to use a little more robust plug-n-play setup like the Tigertronics SignaLink.
However setup information if you want to use the G90 and SignaLink together is sketchy and incomplete. I’ve spent a lot of time searching, and cobbling together the pieces from various sources including help from a couple of Elmer friends (Norm K7NWF and Don WQ1E) to get it working, so I’m going to document my own digital setup in this post in the hopes that it might be useful to someone else to have it all in one place.
What you will need:
- Xiegu G90 Radio
- SignaLink USB (SLUSB8PM) properly jumpered (SLMOD6PM) for the G90
- SignaLink 8-pin Mini Din Cable (SLCAB8PM – included with the SLUSB8PM SignaLink, but you can buy one separately if needed)
- USB B to USB A Cable
- WSJT-X Software
(Note: No rig control – You’ll need to tune the radio to frequency yourself because the closest thing you’ll find to the G90 rig control commands are in the ICOM family of radio profiles, and not everything works properly in those profiles.)
Connect the Radio’s rear Accessory port to the SignaLink RJ45 jack using the 8-pin min-Din cable. Be careful to line up the arrow on the 8-pin connector of the cable pointing DOWN. The cable fits one way only and you can damage the socket or cable pins if you try to force it in the wrong way. (Ask me how I know that, I dare ya =) )
Connect the SignaLink to your computer’s USB port using the USB B to USB-A cable.
The computer should automatically install the drivers and treat the SignaLink as a USB Audio Codec device.
Computer Audio Configuration:
In your control panel, set the default Sound Playback and Recording devices on your computer to the regular speakers and microphone. (Your SignaLink should NOT be handling the regular computer system sounds, just the communications for the radio through the WSJT-X software.)
G90 Radio Configuration:
These settings come from OH8STN’s helpful video.
VOX – Enable VOX for the PTT setting
Line Input – Change the input from Mic to Line Input
Input Audio Levels – Set input Audio levels to 10.
Audio Out Level – Leave set to 15.
AGC – Turn AGC Off (Should Show AGC– on the display)
Power Level – Set to around 18w
Set the TX knob about halfway.
Set the RX knob about halfway.
Set the Delay knob to 0.
Open the WSJT-X Software.
In File > Settings
General Tab – Fill in your Callsign and Grid Square
Radio Tab – Set Radio to NONE. Set PTT Method to VOX
Audio Tab – Set the Soundcard to select your SignaLink USB Audio Codec in the Input and Output dropdowns.
Set the Power between the top two marks in WSJT-X on the right hand part of the screen.
You should now be ready to tune up your antenna to the chosen band, run the auto-tuner on your G90, and start making contacts!
UPDATE: SignaLink and ALC – Maximizing Transmit Levels
As I’ve been working with the SignaLink on FT8 and FT4 I’ve noticed that you can use the SignaLink TX volume knob to control how much power is going to the antenna and maintain the ALC (Automatic Level Control) at acceptable levels.
The way I do this on the G90 is that I watch the red arrows on the display as they radio starts transmitting. Ideally, they should be filled in red all the way across. If there are fewer than 6 arrows, or you see any part of the last arrow showing as yellow, gradually turn up the TX knob till all six are lit up red.
Then look at the ALC number shown below at the right hand side. If it’s 100 percent, there is no level control being applied and you have the volume spot on for full transmit power.
If you see ALC as something less than 100 percent, then the radio is turning the sound DOWN on you, and you have it a little too loud. (100 percent on the G90 means full sound levels going out, no sound dampening being applied.)
In that case turn the TX known down gradually till you see it just at 100 percent, with all arrows still red.
This can change as you’re transmitting over a period of time, so glance at it periodically and adjust as needed to bring it back to full power, but not so loud that the radio starts to employ ALC.
You can get away with 95 or 96 percent showing on ALC with the G90 without too much outgoing signal distortion happening, but any more than that, and you might have trouble making contacts.
(Thanks to Norm K7NWF for initially drawing my attention to the control of signal output with the TX knob!)