Windows 10 64B laptop to Digirig to KX3. KX3 cable set.
Followed the video instructions from WC0O. CAT control works ok but am unable to figure out why the rig won’t transmit. Checked the obvious- power, PTT settings in KX3, etc. May be a WSJT-X setting as I’m not getting the PTT test button to illuminate.
Marc, W4MPS

Please post the screenshot of the WSJT-X configuration. We’ll go over it.

With the help of Denis K0TX, and following Frank’s (WC0O) setup instructions, my Digirig is now functioning beautifully with my KX3. Per Denis’ suggestion, I am attaching 2 screenshots of my WSJT-X configuration with my particular KX3 and laptop FYI.
Tnx for getting me on the right track
Marc, W4MPS


Mine is similar- I use 19200 baud, and CAT PTT. I hadn’t seen this earlier or I’d have tried to help.

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Hello all, I’m having problems getting the TX light to illuminate on my KX3 as well.

In the “Radio” tab under “Serial Port” I don’t have the “COM8” option available though. I have:

I’m using a MacBook and a digirig in conjunction with the KX3.


Try lsusb command in the console. That will dump the info on all USB devices. The one that has Silicon Labs in the description is Digirig’s serial port.

ran “ioreg -p IOUSB -l -w 0” and got this:

“sessionID” = 2544906735111
| “USBSpeed” = 1
| “idProduct” = 60000
| “iManufacturer” = 1
| “bDeviceClass” = 0
| “IOPowerManagement” = {“PowerOverrideOn”=Yes,“CapabilityFlags”=32768,“MaxPowerState”=2,“DevicePowerState”=2,“DriverPowerState”=0,“ChildrenPowerState”=2,“CurrentPowerState”=2}
| “bcdDevice” = 256
| “bMaxPacketSize0” = 64
| “iProduct” = 2
| “iSerialNumber” = 3
| “bNumConfigurations” = 1
| “kUSBContainerID” = “82fbc78e-84e5-4015-854d-f17679200709”
| “USB Product Name” = “CP2102N USB to UART Bridge Controller”
| “locationID” = 34734080
| “bDeviceSubClass” = 0
| “bcdUSB” = 512
| “kUSBSerialNumberString” = “561d6d438766ec11966b1f42ef680de7”
| “USB Address” = 3
| “IOCFPlugInTypes” = {“9dc7b780-9ec0-11d4-a54f-000a27052861”=“IOUSBHostFamily.kext/Contents/PlugIns/IOUSBLib.bundle”}
| “kUSBCurrentConfiguration” = 1
| “bDeviceProtocol” = 0
| “USBPortType” = 1
| “IOServiceDEXTEntitlements” = ((“com.apple.developer.driverkit.transport.usb”))
| “USB Vendor Name” = “Silicon Labs”
| “Device Speed” = 1
| “idVendor” = 4292
| “kUSBProductString” = “CP2102N USB to UART Bridge Controller”
| “USB Serial Number” = “561d6d438766ec11966b1f42ef680de7”
| “IOGeneralInterest” = “IOCommand is not serializable”
| “kUSBAddress” = 3
| “kUSBVendorString” = “Silicon Labs”
| }

Do you have a PC to try the Digirig there? Just to rule out any hardware issues.
Also I don’t remember seeing Hamlib errors mentioning USB. Maybe a Mac thing, but typically the error talks about the serial port. Let’s also look at the settings screen for WSJT-X with the CAT ports list expanded.

here’s the current settings. I’ve been trying different options.

See Marc’s screenshot earlier in the thread for settings known to work with KX.
If you want to troubleshoot one area at-a-time, then you can set rig to “none” and work on making PTT work without CAT first (via RTS).

I did try the settings above. Good advice re: setting to “none”. I’ll try that. Thanks

It worked with these settings.

Awesome, now with the PTT working you can go back to CAT setup.
If it still doesn’t work, confirm that the interface is configured for RS-232.

Just got my Digi. I can get CAT to work, aka the radio keys but I get an error message. Audio seems to working but now, I may show my ignorance. Why am I not getting a frequency read out like I did with Signalink? I wanted Digi for size so bought one. RX level is working but since it doesn’t recognize a frequency, I just get zeros. Do I need Flidgi or a rig interface program? Or am I just not doing something obvious? Or do I need to cut traces? I made an assumption it came configured internally already.


I’m not sure what you mean by “not getting a frequency read”. Are you referring to CAT control or decode of the received audio? Sounds like you talk about CAT control, but Signalink never supported that.

I am not seeing the frequency of the radio in WSJT.

The frequency sync functionality comes from CAT control. If you had it before while using the Signalink then there was another piece of equipment to take care of it. Signalink itself doesn’t support CAT. Digirig does support CAT control internally, but for troubleshooting purposes you can still use your previous serial interface alongside Digirig’s audio to confirm the port settings.

I had the KX3, the Signalink and that’s all. WSJT saw the frequency on the radio or when I did a band change it went along with it. That being said first question, when I buy a Digi for a specific radio does it already have the jumpers or trace cuts done for that type radio or do I have to go in and do them? Second, I did get the keying to work so CAT was working as to a TX closure but was never able to get WSJT to decode although everything else looked correct. I tried several different combinations of CAT, RTS etc., and CAT was what worked. The radio goes into TX but I get an error message, but WSJT won’t place it transmit mode by itself if I activate it in the software. I have tried with both Win 11 and 10 FYI. Maybe I have some radio settings that are not correct or that need to be executed to get the KX to talk through the Digi? Don’t get me wrong, I’m not blaming product for anything, I’m sure its’ the guy in the mirror!



Re. Signalink and CAT control including band/frequency sync between software and radio. I will be interested in learning about this. Will you be able to recreate this setup again and report on it?

Re. Digirig’s serial port configuration:

  1. In Digirig store there is a drop down with 4 different options. It is up to the buyer to select the correct configuration (Elecraft KX uses RS-232 configuration). If I see an order with the combination of cables and Digirig configuration that doesn’t make sense I reach out to the buyer to confirm if that was intentional.

  2. Digirigs sold at Gigaparts are offered as kits for particular transceivers so everything is preconfigured and should work out of the box

  3. With Amazon and eBay, based on my previous experiences I have a dim view of the their shoppers’ abilities to read descriptions and research products so the only option available there is Digirig in its default configuration and only cables listed are those that work with the default configuration.

It is quite possible that your Digirig is not configured for Elecraft KX if for example you ordered Digirig from Amazon and cables from the digirig.net store. You can always check the configuration by opening the case and looking at the solder jumpers configuration (info here).

Re. PTT: the fact that it works doesn’t indicate a working CAT control. Although Digirig supports PTT via CAT command, PTT can also be configured via RTS signal and VOX. Signalink only supports internal VOX. What I suspect happened in your case with CAT triggering PTT is that you probably had hardware flow control enabled and when software tried to communicate with the transceiver it activated RTS signal which in turn tripped the PTT. I would have to see the rig configuration screen of WSJT-X to discuss your settings. With decode not working I suspect we’ll need to look at audio tab as well.