Adjusting ALC on Vara HF and Winlink

I have an Elecraft KX3 connected to a digirig I find that there are two spkr/mic choices for digirig. One lists the USB card and the other the USB-4 card. I have tried to set the ALC on my KX3 using straight USB soundcard input from digirig and could not get a transmit tone through Vara soundcard setup. I changed to the USB-4 and got a tone at full scale but was unable to change the alc level except on the rig. I then went back to the original USB soundcard input and it now worked, but still no control over the ALC level. Can someone tell me why I have two sound card inputs from digirig, and why i cannot adjust the ALC on Vara FM.


Terry, N7TB

Can you please share the screenshot of the entities you are describing?
Is this something you see in the Device Manager? Control Panel?

Hi Denis,

I have done some additional testing. Everything works fine with WSJT-x and JS8Call. There are two soundcard device choices associated with the digirig in all programs. Image 2 shows both USB and USB-4 as choices. I can only key the KX3 transciever in Winlink through VARA HF with using USB-4 for both speakers and Microphone.

Image 0 shows the setup for Vara HF. When I enable RTS, as soon as I open the session window and Vara loads, my KX3 transmit light comes on and a low level signal is being transmitted as showing on my K4 screen above the KX3, in image1.

When I start session, the actual transmission starts and the signal sounds as it should, but when it times out, my transmission light is still lit and the low level signal is still there.

I can only upload one image per post, so this one has image 2.


Any thoughts?

Terry, N7TB

Here is Image 0


Terry, N7TB

Here is image 1


Hardware flow control options should be disabled/turned off:


When that is turned off, the KX3 will not transmit.


That would come from PTT settings.
Try different options in that section involving RTS over Digirig’s COM port.

Hello Terry.

I came across the same issue regarding ALC on Vara FM. After a lot of searching and reading, the final conclusion is ALC is not functional on FM.

Copy and pasted from a post I found:

“ALC: really has no purpose on FM…audio on FM is thru the “deviation” control circuit.
However depending on rig, your “mic gain” still has some control.”

I hope this is hepful.