Harry, This isn't a switch it on and off again problem I am afraid. It is simply that the KX3 Data Mode is restricted in bandwidth at the low end, unlike the SSB mode on the same radio. Bizarre but true.
73 from David GM4JJJ > On 3 Jan 2017, at 00:00, Harry Yingst via Elecraft <elecraft@mailman.qth.net> > wrote: > > Back when I was playing with SDR's I would notice the same thing (Deep nulls) > Sometimes resetting the software (or turning the rig on and off again) would > cure it. > > Something to try > > > > > From: Nicklas Johnson <n...@n6ol.us> > To: elecraft <elecraft@mailman.qth.net> > Sent: Monday, January 2, 2017 6:54 PM > Subject: Re: [Elecraft] Audio artifacts in DATA A mode with KX3 > > 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 <n...@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. > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to hlyin...@yahoo.com > > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to gm4...@yahoo.co.uk ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com