[Elecraft] Audio artifacts in DATA A mode with KX3

[David Anderson]

Many thanks and a Happy New Year to all!

73 from David GM4JJJ

> On 3 Jan 2017, at 21:46, Nicklas Johnson <nick at n6ol.us> wrote:
> 
> Thank you, Wayne!  At least we know we're not crazy :-)
> 
>    Nick / N6OL
> 
>> On 3 January 2017 at 13:45, Wayne Burdick <n6kr at elecraft.com> wrote:
>> This is on the KX3 firmware list. I'll move it up a notch.
>> 
>> Wayne
>> N6KR
>> 
>> 
>> On Jan 3, 2017, at 12:16 AM, David Anderson via Elecraft <elecraft at mailman.qth.net> wrote:
>> 
>> > Nick,
>> >
>> > Thank you for bringing this up.
>> >
>> > I never did get a satisfactory explanation, I contacted support too but that didn't get me anywhere either, I don't think they understood my question, which is quite simple really, why can't we get the same bandwidth in Data mode as in SSB mode? I think it's a simple oversight, but nobody seemed interested in acknowledging it or fixing it.
>> >
>> >
>> > 73 from David GM4JJJ
>> >
>> >> On 2 Jan 2017, at 23:54, Nicklas Johnson <nick at n6ol.us> wrote:
>> >>
>> >> Jörg in the Elecraft KX3 group on Facebook had an interesting observation:
>> >> with WJST's waterfall, if the "flatten" mode is on, it produces some
>> >> unusual artifacts in the presence of sharp spectrum drop-offs, and indeed
>> >> if I turn off the "flatten" feature and manually set the zero point for the
>> >> waterfall, the artifacts go away.
>> >>
>> >> It's still an open question as to why the data-a mode has a steep drop-off
>> >> at 400Hz when the PBT settings on the rig would seem to indicate otherwise,
>> >> and the same drop-off isn't there in USB mode.
>> >>
>> >> I see searching on "400 Hz" that GM4JJJ had the same question here on the
>> >> last back in July 2015, but never really got an answer.  I basically have
>> >> the same question as this one:
>> >> https://www.mail-archive.com/elecraft@mailman.qth.net/msg183837.html
>> >>
>> >>  Nick
>> >>
>> >>
>> >>> On 2 January 2017 at 12:06, Nicklas Johnson <nick at n6ol.us> wrote:
>> >>>
>> >>> I'm seeing some unexpected audio artifacts when using DATA A mode with the
>> >>> latest production firmware on my KX3, on all bands.  This is something I
>> >>> observe when the PBT BW is set all the way wide (4KHz) and FC is centered.
>> >>>
>> >>> In DATA mode, there's an audio drop-off between 200 and 325 Hz, with an
>> >>> almost completely dead audio "hole" between 250 and 300 Hz.  Then there's
>> >>> some additional noise between 350 and 500 Hz.
>> >>>
>> >>> If I switch to USB mode (with no EQ or audio effects applied, naturally),
>> >>> all of these artifacts go away, and it's perfectly smooth across the
>> >>> spectrum.  No drop-off, no noise.
>> >>>
>> >>> Pictures of the waterfalls for comparison here: http://imgur.com/a/AjHu4
>> >>>
>> >>> Am I doing something wrong, or is there something I should check?  I've
>> >>> taken the usual steps, but it's plausible I've missed something.
>> >>>
>> >>> ​   Nick​
>> >>>
>> >>> --
>> >>> *N6OL*
>> >>> Saying something doesn't make it true.  Belief in something doesn't make
>> >>> it real. And if you have to lie to support a position, that position is not
>> >>> worth supporting.
>> >>>
>> >>
>> >>
>> >>
>> >> --
>> >> *N6OL*
>> >> Saying something doesn't make it true.  Belief in something doesn't make it
>> >> real. And if you have to lie to support a position, that position is not
>> >> worth supporting.
>> >> ______________________________________________________________
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>> >>
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>> >
>> > ______________________________________________________________
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>> 
> 
> 
> 
> -- 
> N6OL
> Saying something doesn't make it true.  Belief in something doesn't make it real. And if you have to lie to support a position, that position is not worth supporting.