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
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.
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.
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.
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.
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
for handling and addressing all these issues for the world’s
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.