locked Re: Windows 10 -WSJT-X power slider help...

Bill Somerville

On 23/07/2019 21:49, W7CD John wrote:

Ø  The Windows mixer control behaves differently with the 64-bit version of WSJT-X, it is no longer controlled by the "Pwr" slider in WSJT-X. You must adjust it manually which should be a one time operation. The best way to adjust it is to click "Tune" in WSJT-X to get a transmission started, you can have the rig power at minimum while you do this adjustment. You need to have the "Sounds->Playback devices->'your-selected-output-device'->Properties->Levels" visible with the slider therein set to decibels (right-click and select decibels). Set the WSJT-X Windows Sound Mixer slider to maximum, that will also push the master level for that device to maximum and you will see a corresponding change to the device level slider you previously opened. If the device level slider shows 0dB then you are done, if it shows higher than 0dB (e.g. some devices can go to +14dB) then you *MUST* reduce the device level slider back to 0dB. This last step will automatically reduce the mixer WSJT-X slider and the mixer master level slider, and that is fine so leave them alone.

Hi Bill.

I’ve followed this procedure carefully here and compared the result between both the 32 and 64 bit versions on my Win10Pro PC.  BTW, the Level on my output device (Flex DAX Audio Tx <not the IQ one>) will not exceed 0dB.

On a 100W-max Flex, the 64bit version cannot be made to exceed 28W when you hit Tune.  For the 32bit version, 75W out.  Both of these are into a dummy load.

Not an issue for me, but an interesting benchmark.  64bit operation is worth the power trade-off when the band’s loaded on weekends and the obviously speedier decoding of the 2nd and 3rd pass are worth it.  If there’s an ATNO out there that I can’t hit with those power levels during this Solar Minimus, there’s always the “foot warmer” available.

BTW, I do choose to use the Kenwood TS-2000 to define the Rig, not the FlexRadio 6xxx.  When the PC gets really busy (WSJT-X, N1MM+, JTAlertX, Log4OM, Log4OM Communicator, PSTRotatorAz, SmartSDR, SmartSDR CAT, Smart DAX, with OS profile management in a Windows NT-domain), I’ve experienced some latency issues with the latter control.  When I tried SO2R with 2 instances of WSJT-X 2.0.1 GA during RTTY RU last January, I almost brought this decade-old  Intel i5 3GHz PC to its knees.  I’m hesitant to push it that hard again.  J

Thanks for handling and addressing all these issues for the world’s operators! 

73 John W7CD

Hi John,

it's good that the DAX devices will not add digital gain. VAC can but also can be disabled in that case.

You should get exactly the same power output between the 32-bit and 64-bit versions of WSJT-X if the Windows mixer control for WSJT-X on the DAX Tx speaker device is set to maximum (this is based on your assurance that the DAX input devices have no digital gain). You are missing something when carrying out the procedure above is you are not. Once the one off procedure above has been executed the WSJT-X "Pwr" slider should behave the same for either version although you may find the granularity of steps slightly different and there may be some small discontinuities as you slide the "Pwr" control up and down with the 64-bit.


Join main@WSJTX.groups.io to automatically receive all group messages.