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Question for Tim and other WSJT-x Users

Bill-W9OL Member
edited June 2020 in SmartSDR for Windows
I'd had my 5K working JT for a while.
And Tim's April 2014  instructions on wsjtx with DAX were great for the 6K.
I have  wsjt-x on both the 5K and 6K.
Both work well, (not at the same time. LOL) (different folders)

But I see a couple of major differences which I assume is related to DAX.

1. 5K, I hear a normal transmit sound and see a reasonable display upon transmit
    6K, I do NOT hear any audio when transmitting and the display on screen is very intense, filling the whole screen modulating in sync with what would be the audio if I could hear it.
I've tried headphone and powered speakers and am obviously missing the setting to apply the what I'm calling "sidetone".
I know I'm getting out...as I'm working stations.

I'm getting my head around DAX, but it's thick (the head) and it's slowly getting through.

Still not clear on the difference between
a DAX RX and a DAX RXIQ  I was able to understand a DAX TX Audio though :-)

If there is a 'article' on this, someone please send me the link.


  • George KF2T
    George KF2T Member ✭✭✭
    edited February 2019
    Hi Bill -- no "sidetone" (monitor audio) with DAX, so you're okay there. Also, the panadapter does go a bit wild on transmit. It may be a bit too sensitive in transmit, and does seem to show "stuff" that isn't "really real." 

    DAX RX is an audio-based stream, where the IQ is a much broader sample of the passband, delivered as an I/Q signal instead of audio. I'm hoping we can do JT-modes with it someday. Mostly, I think it's used by the CW Skimmer folks at the moment.

    Hope that helps!

  • Al K0VM
    Al K0VM Member ✭✭✭
    edited November 2017
      DAX RX is the same audio that you would hear on a speaker/headset. It's the demodulated audio and is used by most sound card programs that you use..  DAX IQ is a raw stream of un-demodulated data that is much wider ( up to 48Ksps to 192 Ksps ) and can be use to pass a wide spectrum of signals to an external program (CW Skimmer).

     The current versions of SSDR do not allow listening to the transmitted signal in DIGI modes.

     I normally change the vertical scale on my panadapter so that the top of the screen is -20 DB and the bottom is -130 of so.. That way, in transmit, the whole signal appears in the panadapter. 

    AL, K0VM

  • Bill-W9OL
    Bill-W9OL Member
    edited October 2016
    thanks gentleman. that tells me that not hearing the 'sound of the transmitted' signal is not a mistake in my setup.
    Does seem odd as it the only digital mode I've worked that doesn't provide a transmitted audio.
  • KY6LA_Howard
    KY6LA_Howard Member ✭✭✭
    edited June 2019
    Funny... I work digital modes (JT9/65, PSK, RTTY, Olivia) all the time... I always turn the sound off on both Send and Receive...

    I really don't see the need to listen to anything as I can see everything perfectly well on the Panafall
  • Andrew O'Brien
    Andrew O'Brien Member ✭✭✭
    edited August 2014
    You CAN get your transmitted audio to be played via your computer so that you can hear it .  I do it all the time because my brain is not comfortable with being unable to hear my audio.  In fact I think it VERY odd that Flex does not make this standard in SmartSDR with DAX, To achieve this you have to use Windows sound to route you transmitted audio to you speakers. I can't remember how to do it but it is very simple, search the user community for a email from me on the topic.  I asked the same question a few weeks ago and received helpful answers.  For good quality transmitted tones , use the DAX TX slider control and check you ALC levels in the TX tabs within SmartSDR.
    Andy K3Uk
  • W5XZ - dan
    W5XZ - dan Member ✭✭
    edited December 2016
    seems like there's 3 ways to set the audio drive with WSJT-x; power slider in WSJT, on the right; DAX TX, and mike gain in the radio...several settings seem to work, not sure which combo is 'best'...      73, w5xz, dan

  • Patrick
    Patrick Member ✭✭✭
    edited June 2020
    DAX is capable of presenting streamed data in two forms.  Bit rate sampled audio or I/Q data which is frequency and amplitude over a wide frequency range sometimes 48Kh, 96Khz and 192Khz, representing Data sampled IF, which is used by other apps to decode signals.  The Bit rate sampled signals are already decoded into a digaital data stream representing only the audio which is closely related to what you find on a CD.  Different data rates can be selected in the PC.  I believe the data in the DAX stream is 24KHz sampled.  But you can set the PC audio to any multiple like 48Khz for ease of processing by the processing app like DM780 or WSJT. 

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