Friday, 19 February 2021

Multiple instances of WSJT-X - using more than one radio, or two data streams on the IC-9700

Imagine the situation. You have just bought a shiny new radio. You want to receive and transmit data on it, but you still have your old one hooked up. You could be, say, monitoring HF and VHF at the same time, or indeed any combination of bands between the two radios. You might want to transmit on more than one band at once, or monitor more than one mode on the same band.

Or maybe you just want to leave both radios hooked up but sometimes use one or the other. You cannot be bothered to keep switching about in the WSJT-X settings. Well, here is the answer. You just click which ever one you want and up it comes. Close it and open the other one to change rig. Easy.

You can see the result here below. From left to right are the readouts from my IC-7300 on 4m, IC-7100 on 70cms, and IC-9700 on 2m. There is in fact a reason why they are arranged in that order - the radios have to be in the same order on the bench below for space reasons - and it works for me. I have a separate display screen for this display. The object of the exercise is so that I can follow propagation up and down the bands, which is what I watch very carefully.

WSJT-X display at GM4FVM showing three instances running at the same time


As usual, click on the images to enlarge if you need to.

The WSJT-X home page leads you to a guide to WSJT-X which explains that this is easy to set up but then seems to be a bit vague about how to do it. There is a link to the WSJT-X home page on the side bar to this blog and you can go there and see if it makes sense to you.

For me, I use a slightly different system for setting it up, but I achieve the same result in the end. I have recently been using both data channels of audio from the IC-9700. In effect this creates a new radio to monitor - the "IC-9700 Sub band" radio.

Up to now I have been using MSHV to monitor the IC-9700 Sub band. This works fine but MSHV does not cover the JT4G mode used by the GB3NGI beacon so I have to switch to monitoring 23cms on the Main band and then 2m is on the Sub band and I cannot transmit on that so I have to keep switching ... ...  look, never mind about all that. Let us just say that I am about to set up another instance of WSJT-X and I thought I should show you how I did it.

Please note that what I am describing is for Windows PCs only. This is because I know very little about other operating systems (what makes you think that you know much about Windows either, Jim?). I suspect that the same thing is possible in other operating systems, it is just that I have never tried it. Someone familiar with other OS arrangements can probably translate it to them fairly easily.

It is simple enough. First you create a new desktop shortcut to point you to a new rig name in WSJT-X. Second you need to create that new rig name in WSJT, which is fiddly. With my method you do them in that order. After that you can use the desktop shortcut to open the new instance and set it up as usual in WSJT-X. You can run either instance separately or both together. This new one will make four for me.

You are probably best to rename your old rig too just to tell the difference between them but strictly speaking you do not need to do this as a third stage.

The FVM method

OK, my first step was that I found my desktop icon for WSJT-X, right clicked and click "Copy". This gives you a copy of a link you are going to use to open the second (or later) instance of WSJT-X.

You now need to paste the second link to the desktop so that you can decide which one (or both) to open at any time. It should be obvious already that these icons are going to need different names so that you can tell them apart and know which one to open.

When it comes to pasting the link, find a place on the desktop (you can move it later) and paste it there. It is important to paste it as "PASTE SHORTCUT" and not just paste. If you click just paste it will just paste the image and you will spend a lot of time clicking on nothing. I Know, I Was That Solider.

OK, right click on the desktop and click "Paste shortcut". The icon will appear with a title attached which will be something like WSJT-X (2) with a version number. You need to right click on this, click "Rename" and give it a title something like "WSJT-X Banjo 3000" (this would mean most if your new rig is indeed a Banjo 3000, otherwise use the name of the rig). Then you might want to do the same with your first version of the shortcut and rename that "WSJT-X Old Rig" or some suitable title like "WSJT-X Yaesu FT-897".

You do not really need to retitle them if you can cope with WSJT-X and WSJT-X (2) for titles but I got totally lost with that. When I had two IC-7100s I called one A and one B but it was still mightily confusing. Perhaps it is best to use easily recognisable titles.

Probably best to give them meaningful names

OK, you have two shortcuts with different titles but you cannot open these together because they both point to the same "rig name" in WSJT. Confusingly WSJT needs a different rig name too and it gets very stroppy if you try to open the same name twice.

This is a simple idea - you just add some text into the "Target" box of the shortcut. You need exactly the correct text.

I went to the new shortcut I had pasted and right clicked to show the "Properties" screen.

Your addresses in "Target" and "Start In" will be different from mine for reasons of my stupidity in the past, but ignore that. All you need to do is add on to the end of the "Target" line a suitable text element. The snag is that the text has to be pretty specific.

After the .exe ending you add a space then --rig-name=Banjo3000. Right so that is-


followed by your rig name.

In my case  --rig-name=IC9700SubBand

Don't forget the starting space, the dashes are the middle of the line ones, not "underscore". You rig name can be anything but maybe it is a good idea to make it the same as the name you gave the shortcut. Less chance of confusion if you call it the Banjo 3000 all the way through. Or Kenwood TS520 or whatever. For the name I do not use spaces, strokes, dashes or odd symbols, just letters. There are enough dashes in the target line already.

Then click "Apply".

You might, as I say, change the name of your original rig in the target line of its shortcut too. You do not really need to so long as you remember that "the rig with no name" in WSJT-X is the first rig. 

Basically that is it.

I have no room for another instance of WSJT-X on the left hand display along with the other three, so it has gone on the right hand display which I use for PSK-Reporter. As I test I used the 2m beacon to check everything out.

IC-9700 Sub band being decoded on the new instance of WSJT-X

 Normally I use it for monitoring 1296 MHz so it does not see much decoding action. 

You can move the WSJT-X panels and wide graph about by clicking on the top bar, keeping the mouse button pressed and dragging them about. You could put two beside each other. Within limits you can resize them and also juggle about the graph scales to make it all fit. You might want to put the two of them beside each other, or whatever you choose.

You are now free to choose between which instance of WSJT you want to open or open them both together. Or in my case, four together (but I am a nerd). I have put some stuff about PC processing capacity while running WSJT-X at the bottom of this posting. Unless you have more, fairly ambitious, plans it is unlikely you will run out of computer power just by adding a second instance.

As I said, you can move the WSJT-X panels anywhere on your display screen. If your PC screen is already cluttered you might want to add another display screen. This is a good use of that old screen you put in the attic - it can do the mundane email stuff and let your fancy new screen show WSJT-X off to maximum advantage. If you have multiple display screens you can do bizarre things, as I have done. You will need a suitable display board to run more than one screen (though many laptops and fairly basic PCs can run two). But if you are happy with both instance on your main display screen you do not need to bother about any of that.

You might need to juggle connection standards for multiple screens - I am using one each of SVGA, DV-I and HDMI plugs. Adapters and gizmos to help are available and you can now sometimes use advanced USB sockets for even more display screens.

If all you are doing is switching between two rigs then this will cause no PC processing problems at all. Two instances running FT8 together should be fine too. Once you get beyond two instances it might become a bit more difficult in terms of processing power. This might be particularly true if running multiple versions of, say, MSK144, which uses a lot of processing power. If so, see below.

Over to you now that you have set up two instances of WSJT-X.

Icom IC-9700 [EDITED 24/2/21 re sound card setup]

I will carry on and explain how I set up the second instance of WSJT-X to decode the Sub-band on the IC-9700.

First you need to have your PC sound card set up to receive two channel ("stereo") audio. Windows sets it up for mono by default. For this see my earlier posting here.

 Or you can look up the site which set me off on this path (which is better written than mine)

Note that on the Klop site he used a lower audio bit rate which might save you a bit of procesing power, but I doubt that will matter much.

Anyway, assuming that you PC is ready. let us go back to the tale of the WSJT-X setup.

As the Sub band has no CAT control and it is not possible to transmit from it, all I am doing is a receiving set-up.

Lack of CAT control means that in "Radio" settings I set Rig to "None", port to "USB" and PTT to "VOX"

Radio settings for the IC-9700 Sub band.

In "Audio" I set Input to the IC-9700 soundcard and right hand channel. Output is irrelevant as there is no transmit, but I set it to the PC speakers to remind me just in case I stuff it up someday and try to transmit.

Audio settings for Sub band on the IC-9700.

If I get time I will post something about what you can do with the IC-9700 in terms of cross and split band operation now that you have set up more than one instance of WSJT-X.

PC processing power issues.

It is possible that you could outrun your computer processing power if it is already running short. Running multiple instances puts more strain on your computer, and a fair bit extra if you use multiple displays. Most modern computers can handle it. 

With three display screens and four instances of WSJT-X this is an issue for me, but would not be for most operators. Because I specifically monitor multiple bands I have higher than normal usage.

I used to have problems with this but not after upgrading to a fairly low-spec second hand gaming computer.

With my setup - Intel Core i5-7400, 3GHz, and 16GB of ram, running W10 20H2, four instances of JT65 involves my machine using 35% of CPU and 38% of memory. Four instances of MSK raises this to up to 50 to 60% of CPU - but I would never expect to find myself running 4 instances of MSK. Note that this is only WSJT processing load, in my case the displays are run from a separate board.

I think that multiple instances are more likely to create issues with display processing than running WSJT. After problems in the past (back in the days of Pentiums, but an elephant never forgets) I have always fitted a higher spec display board to handle all three displays.

For this reason if you do decide to go for multiple display screens it might be worth considering a gaming-type display board with lots of on-board processing capacity to handle the displays (mine use 1.7Gb on a NVIDIA GTX1050 display board, but use virtually none of the main processor capacity as a result). But for most situations it will all work fine.


Running multiple instances of WSJT is a simple step to take for the many individuals who use two rigs, say for HF and VHF. The danger is that you get carried away. You start running many instances, you need multiple display screens to cope with all this and watching dx Maps and PSK Reporter at the same time, you need a bigger computer, you need more antennas, more masts, more rotators, you need a bigger shack, you need another job to pay for all this, ARRGGGHHH. 

More of my life story later. 




P.S. Sorry, like every posting there is bound to be a typo in there somewhere. If this is stopping you getting WSJT to work I will try to update any flaws if I find them. Good luck and enjoy it. Jim


  1. Interesting article again, Jim.

    I have set up second instances of WSJT-X shortcuts in the past. I have an extra one for the 'dark' alternative WSJT-X display but rarely use it.

    I still need to get my head round the problem of having two instances of Microphones in Windows but WSJT-X always wanting to use the 'default' microphone. That's stopping me from monitoring both the TS2000X and the IC-9700 at the same time at the moment here, as only one microphone can be 'default'.

    Cheers - Dave (G0DJA)

  2. Update - After some head scrattching and trial and error with the settings for the two audio CODECs (Called "3" and "4" USB audio CODEC on my PC) I managed to get all three channels sorted.

    On the number "3" CODEC I set the speakers and microphones to be the default speakers/microphone and, on number "4" I selected "set as communications device'.

    Now I have three instances of WSJT-X running. Two monitoring the two audio channels from the IC-9700, adjustable through the "USB AF/IF Output" menu in 'connectors' under 'Set' from the Menu on the IC-9700, and the third is monitoring the output from the TS2000X, which I control via a US Interface Navigator, which acts as an external soundcard for the TS2000X.

    I've seen some FT8 decoded on the sub-band of the IC-9700 on 2M with a simple dipole, but 23cm and 6M are both quiet at the moment.I might swap the TS2000X to one of the HF bands for a while, just to see if it's decoding OK.

    Cheers - Dave (G0DJA)

  3. Jim/Dave - Been through a pile of the 9700 options and can't find the setting to set Left / Right on the USB line. Yes can change the phone sockets (Front and rear). I can set the levels Ok but can't find Sub to Left and Main to Right (or otherway round) - Any pointers? - Tom GM8MJV

  4. Tom/Dave, sorry for the delay in replying - Blogger does not send me comments directly and sometimes it takes a bit of catching up.
    Dave the way Windows allocates sound cards is just plain daft. It comes from an era when home computers were just starting to handle audio. Beware that if you switch the USB plugs into different sockets the audio and COM might (probably will) change and then they need to be set up again.
    Three instances should solve your needs for now. I still need to work you on the three 9700 bands.
    Tom, I have sent you an email which I hope you get. In the meantime I think that I should have added a link to the page above which explained the need to reset the PC audio card to "2 Channel" operation. This is not explained in the Icom manual (Grrr). Hope this answers the point but let me know if it doesn't.
    The earlier post here is
    and this is better than mine ...
    I will add a link to all this above.
    73 Jim GM4FVM