WSJT-X Split Operation and Why Use It


I'm an Amateur Radio enthusiast. I love the hobby and experimenting with radios, antennas and software. On my YouTube channel I upload videos on the Icom 7300 and Icom 7610 along with Ham radio software programs. I hope to inspire people to try new things in Amateur Radio.

40 Responses

  1. Steve says:

    Doesn’t using split tie up twice as much band width??
    The FT8 band portion is already crowded most times

    • K0PIR says:

      Hi Steve,

      Nice to hear from you and that’s a very good question. Using Split Operation, there’s no question is doesn’t, but I think you are referring to plain old split when making QSO’s. According to the experts, the short answer is no. See section 9.3 in this Hinson Tips for HF DXers.

      Here’s his explanation:

      Each party to a QSO transmits in a different period. Even and odd periods are orthogonal or independent, and should be considered separately. Within each period, each party is using one thin slice of spectrum, just 50 Hz wide. After they end their transmission, their transmit frequency is then released for anyone else to use. See Appendix E for a more elaborate explanation.

      What do you think?

      Rich, K0PIR

  2. Earl Palmer, N7EP says:

    I am very impressed with FT-8 and us it a lot. However, I don’t like using split with FT-8 for the following reasons.

    1. When using split the required bandwidth is doubled. When not using split both sending and receiving stations use the same frequency and 50 Hz bandwidth. When using split each station is using 50 Hz for a total bandwidth of 100 Hz.

    2. Split causes interference. A station calling CQ picks a clear frequency and the answering station blindly picks a different frequency that may not be clear for the calling station. This creates the possibility of interference to other stations on those frequencies. This often occurs when a desired DX station calling CQ is simultaneously called by multiple stations.

    When the band isn’t busy, split works fine. When it is very busy split doesn’t work well, creates interference and uses double or more of the bandwidth.

    FT-8 is amazing. I have called CQ and then simultaneously copied and worked 2 or more stations answering on the same frequency.

    It will be interesting to see how FT-8 works out on field day. My guess is that if propagation is good the existing 20 Meter 3 KHz FT-8 window will expand to about 13 KHz or more, perhaps from 14.070 to 14.083 MHz.

    Earl, N7EP

    • K0PIR says:

      Hi Earl,

      It’s nice to hear from you and thank you for commenting.

      If I understand you correctly you are referring to just plain old spilt and not Split Operation, ie. Rig and Fake It.

      When the band isn’t busy, split works fine. When it is very busy split doesn’t work well, creates interference and uses double or more of the bandwidth.

      That’s pretty much how I see it. When the band is so busy it’s hard to find a clear spot to put my TX indicator, hi!

      Thank you so much and I appreciate your taking time to comment.

      I hope to hear you on the air.

      Best 73,
      Rich, J0PIR

  3. Ray Lewis says:

    Rich, I have found that with the 7300, if you use “rig” for the split and you change the band you are operating on, as an example 40 meters to 30 meters, your receiver changes to the frequency that is that your switch to automatically with WSJT-X, but your second VFO does not change frequency on the transmit. The 7300 will try to transmit on 40 meters when you change to 30 meters for receive. Do not have my 7610 set up for WSJT so I do not know if it does the same or not. When you check the “fake it” box, the 7300 switches both transmit and receive correctly. 73, Ray AA4EZ

    • K0PIR says:

      Hi Ray,

      Nice to hear from you and thank you for the comment. I was just on another forum last week and was mentioned the same thing about the 7300. I would have to make sure and sync the VFOs when changing bands. It was a little cumbersome and that’s why I started using Fake It.

      I tried “Rig” with my 7610 and it worked perfectly. I am using The Icom 7610 for the Rig in WSJT-X. Using Ham Radio Deluxe for the Rig in WSJT-X still causes problems for me.

      I was going to go back and test it with the 7300 and using the Icom 7300 as the rig just to see if something had changed.

      Thank you for commenting and thank you for the reminder about the 7300.

  4. Guy G4DWV says:

    Hi Rich,

    Thanks for a nice article as always.

    I always work split and ALWAYS call the DX off his channel. I have had astounding success with this and am surprised that you have not. Okay, I may have to call for over 10 mins, but I invariably snag ’em. I have also started to stop sending the line with my locator. It makes for much quicker QSOs.

    73 de Guy G4DWV 4X1LT

    • K0PIR says:

      Hi Guy,

      Nice to hear from you and thank you for commenting.

      It is strange, but it seems like simplex works better for North American stations. How can it be??? With the software the QSO partner will see my callsign in the RX window just as if I was calling him on simplex. It seems very odd.

      I am wondering if it has something to do with the software and timing. Maybe simplex will be seen 1st by the software if “Call 1st” is checked on the receiving station??? It is a mystery.

      When 20 Meters is so very busy it is sometimes hard to find a clear spot, so it seems using simplex is the only way. I’ll have to look into that some more and see if I am missing anything. How do you find a clear spot or do you go simplex too?

      I appreciate your taking time to comment. I will continue to try it more and see. Maybe it is just a quirk and over the long run it will even out for me.

      I hope to see you on the air.

      Best 73,
      Rich, K0PIR

  5. Deryl, wb4qiz says:


    I am using the Icom 7300, HRD, and WSJT-X with FT8. Audio with Codec, I have followed your instructions with the one USB cable. I get a green signal when I press the button and red with PTT. My problem is I get little power output. I followed all the internal radio connections on the 7300. I am getting signals coming in. I can call CQ and still very little power output. I have the pwr set at 100 watts on the radio and trying to control the slider on the software cannot make the power go higher.


    Deryl, WB4QIZ

    • K0PIR says:

      Hi Deryl,

      Nice to hear from you and thanks for commenting.

      In the radio, look and see if your USB MOD Level is around 40%. You can increase that to increase power. DATA MOD should be USB.

      If you’re using Windows go into the Sound and Playback Devices. Look for the USB Audio CODEC and open it. Go to the Levles tab and see what it is set to. 30 to 50 is a good starting place.

      Set the Slider to 1/2 and try the Tune button. You should have plenty of power. I adjust mine in Windows and then WSJT-X. I leave the radio alone most of the time. Once you get it set, you won’t have to touch those again.

      If you still need to decrease power you can turn down the RF Power on the radio.

      I should do another video on this and WSJT-X. Thanks for the question and I hopes this helps.

      Let me know,

      Rich, K0PIR

  6. Deryl says:

    I did what you said above: however, the radio jumps out of the USB-D when transmitting to USB on 14.074

    I am using the 7300, on the WSJT-X, on settings, the Radio: Rig is Ham Radio Deluxe, Network server is blank, Mode: I have tried all three, None, USB, and Data/pkt, and the rig jumps out of USB-D to USB when transmitting or when it stops transmitting, it jumps out of USB-D to USB.

    Any suggestions?

    Thanks you for all you help.

    Deryl, WB4QIZ

    • K0PIR says:


      Yes, use Data/Pkt for mode. Use Fake it for the Split Operation.

      When using Ham Radio Deluxe for the Rig in WSJT-X I had problems too when using Rig for Split Operation. Use Fake it and it’ll be good.

      Thanks for commenting and let me know.

      Rich, K0PIR

    • John Foster says:

      Did you get a solution on this? I have the exact same problem.

      Best Regards!
      John, KI4PSV

  7. Bob Edge says:

    Hi Rich . Having trouble getting a copy of Ham radio deluxe to match my Icom 7300 ,There are no old copies ,just new available, Are Canadians cut off? Tnx for the great job you are doing, Bob VA3RE

    • K0PIR says:

      Hi Bob,

      Nice to hear from you and I certainly hope not, hi.

      I believe you can download the last free version here.

      It doesn’t have the Icom 7300, but there is a workaround. Just use a different radio (7700) and change the CI-V address and make it the 7300s which is 94.

      I hope this helps.

      Rich, K0PIR

  8. Deryl, WB4QIZ says:

    Thanks for all your help, Rich. I have done everything you suggested, and I am unable to make WSJT-X work correctly. I get one thing working, and another thing messes up. I have tried v. 7, 8, 9 and still, something is not quite right. The latest problem is switching out of USB-D goes out to USB when it stops transmitting. I have tried many different ways. I have probably spent 20+ hours trying to make it work.

    Thanks for all your effort. I am not one to give up, but, I am tired of trying.


    Deryl, WB4QIZ

    • K0PIR says:

      Hi Deryl,

      Thank you for commenting, I am sorry to hear that, but it has happened to me too. After a while go back and try it again. Sometimes when I take a rest, I figure out what the problem is later.

      Today I am not using Ham Radio Deluxe as the rig. I have the Icom 7300 as the Rig in WSJT-X and I can use either Fake it or Rig for Split Operation. I can just leave Ham Radio Deluxe Logbook open and JT-Alert will log into it automatically. There’s a article and video here. I don’t know if you’ve attempted JT-Alert, but it is a worthwhile program for Hams who use WSJT-X a lot.

      I have not Failed:
      I have only discovered 10,000 ways that don’t work.
      Thomas Edison

      Hope to hear your on, take care and 73.

      Rich, K0PIR

  9. Brad says:

    I have been using Rig with my 7610 and notied when it is time to transmit, the radio seems to start, resets and starts again and continues. I can hear the relays click twice. I will try fake it and see what happens. Enjoyed the conversation about split mode. It will make me a better operator. Going to use Hold Transmit.

    I sure wish we could post picture here at your website.


  10. Bill, W9LR says:

    Hi Rich,
    I have 7610, WSJT JT alert. Works ok but VFO changes from USB-DATA to USB by itself sometimes. Any ideas?

    Bil w9LR

    • K0PIR says:

      Hi Bill,

      Nice to hear from you and thank you for commenting.

      In WSJT-X try Data/Pkt. for MODE.

      You may also want to use Fake It for Split Operation in WSJT-X.

      See if that works.

      Rich, K0PIR

  11. Edmundo CE2EC says:

    Hi Rick

    Thank you very much for your blog and even for the time you spend.

    I am reading (Google translator) this part that interests me about how to understand.

    But is it possible that you have some video?

    I will appreciate your response.

    73 Edmundo Ce2EC

  12. Sergey says:

    Hello! Tell me how to set up WSJT-X to work simultaneously with two, with three stations ???

    • K0PIR says:

      Hi Sergey,

      Nice to hear from you and thanks for commenting here.

      Just start WSJT-X and connect to the first station (radio). Then start another WSJT-X session and connect to the second station (radio).

      You could have shortcuts to start these and connect to the proper radio. The shortcut”target” path needs to be something like: C:\WSJT\wsjtx\bin\wsjtx.exe –rig-name=Icom

      I think that will work, I have not tried it yet.

      Hope that helps and 73,
      Rich, K0PIR

  13. K0PIR says:

    What problem are you asking about John?

    If you’re radio changes from USB-D to USB, try using none for Split Mode. Then use your radio to set the mode.

    Rich, K0PIR

  14. Paul W5PGR says:

    Every time I seem to have a problem your channel or page has the answer. I was playing around with the radio and changed it to rig. It seemed to work ok and then in FT8 when the feq split on transmit the entire display would flicker or distort for a fraction of a second. I couldn’t figure it out and moving back to Fake it fixed it.


    • K0PIR says:

      Hi Paul,

      Nice to hear from you and thank you so much for commenting. I really appreciate it. Thanks for visiting my webpage and watching the videos.
      Best 73!
      Rich, K0PIR

  15. Ed Dugo says:

    Hi; i am new to both Ham Radio and Ft-8. Right now I am using WSJT-X on Linux and a Yaesu FT 450D. None is checked under split operation. I find that I do not have to move my Tx frequency on the 450D for qso’s on any band in FT-8 and it works fine. The problem I have is all my contacts are recorded as “wrong band”. The WSJT-X program saves them on the band actually worked, but the receiving station is receiving on a different band. Will that change if I check “fake it’

    • K0PIR says:

      Hi Ed,
      Nice to hear from you and congrats on your station. I hope you enjoy Ham Radio as much as I do.
      Fake It is used to keep your transmit freq. in the sweet spot. I recommend using it.
      I am not sure I fully understand, you are working different bands or different frequencies?

  16. Ed Dugo says:

    What I do is leave my 450D on 17 meters (18.100) and just change bands on the wsjt-x software. It works, but as I said above, I get wrong band errors coming back on station logs (QRZ, LotW, EQSL) from other stations.

  17. K0PIR says:

    OK Ed let me see if I understand you correctly. Your radio is transmitting on 18.100. So even though you switch bands within WSJTX, your radio stays on 18.100. If your radios frequency display stays on 18.100, then that is the band you are transmitting and receiving on regardless of what WSJTX indicates.
    If you switch bands with WSJTX and your radios not switching bands along with it then you do not have rig control.
    Did you setup rig control in WSJTX and press the TEST and TEST PTT in the setup page? WSJTX frequency display should be the same as your radios.
    Let me know. I’m not sure if I’m understanding you. Best 73!

  18. Ed Dugo says:

    I have flrig software to do rig control. I guess that isn’t working properly as the display on the radio doesn’t change and match the display on flrig. I guess I will have to work on that. thank you for your reply.

  19. Ed Dugo says:

    Sorry about the double post. We had a power flash and I wasn’t sure if it posted.
    After reading your reply I did some checking and found that I never bought the serial to USB adapter cable so the rig control was not working at all. Oops. Thanks for your help



  20. KM6DOV says:

    One thing I noticed when I use the Hold TX Freq is that my Enable TX doesn’t turn off when the caller responds to someone else. With the checkbox off, it will stop my xmit. It seems like the logic only applies when it sees someone else’s call on the Tx freq. Any way to enforce good behavior here?

    • K0PIR says:

      Hello and thank you for commenting.

      That is a very good point you make and many operators will continue to call the station even though they are busy. Many are not very familiar with FT8 and WSJT-X. Hopefully it is just a learning curve.

      I will try to remember to make your point in my next video and put it in writing.

      We could make TX Macro “Wait Your Turn”. Hi Hi!

      Thank you again and best 73, stay safe!

      Rich, K0PIR

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