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KX3: Is this a serious error in KX3 Firmware affecting the IQ output?

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tomb18

KX3: Is this a serious error in KX3 Firmware affecting the IQ output?

Hello,I received reports recently about the signal peaks that are seen in software based panadapters appear to shift by approximately 1.25kHz when the bandwidth control is changed from 1.8 to 1.7. in USB mode on the K3

At 1.8 the IS command returns 1500 in USB and the BW command returns BW0180
AT 1.7 the IS command returns 1500 in USB and the BW command returns BW0170 which is normal behavior.

I have investigated this and it indeed happens when the bandwidth is changed from 1.8 to 1.7
The sound of the signal nor the tuning of the radio is changed. However, a QSY to the original peak will detune the signal.
This has been confirmed in Win4K3Suite, NAP3 and HDSDR.

Can someone check this please on the PX3?
This is on the latest firmware of 2.19

Thanks, Tom va2fsq
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Don Wilhelm-4

Re: KX3: Is this a serious error in KX3 Firmware affecting the IQ output?

Tom,

I don't know the answer, but what I can inject is the fact that the KX3
shifts to Weaver demodulation at some point, it may be at 1.7 kHz.
That would affect the signal peaks without substantially changing the
sound of the signal on the KX3.

73,
Don W3FPR

On 9/22/2014 7:13 PM, [hidden email] wrote:

> Hello,I received reports recently about the signal peaks that are seen in software based panadapters appear to shift by approximately 1.25kHz when the bandwidth control is changed from 1.8 to 1.7. in USB mode on the K3
>
>
> At 1.8 the IS command returns 1500 in USB and the BW command returns BW0180
> AT 1.7 the IS command returns 1500 in USB and the BW command returns BW0170 which is normal behavior.
>
>
> I have investigated this and it indeed happens when the bandwidth is changed from 1.8 to 1.7
> The sound of the signal nor the tuning of the radio is changed. However, a QSY to the original peak will detune the signal.
> This has been confirmed in Win4K3Suite, NAP3 and HDSDR.
>
>
> Can someone check this please on the PX3?
> This is on the latest firmware of 2.19
>
>
> Thanks, Tom va2fsq
>

______________________________________________________________
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Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

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Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]

tomb18

Re: KX3: Is this a serious error in KX3 Firmware affecting the IQ output?

In reply to this post by tomb18

Hi
If this is the case is there any way to determine exactly where or when this happens? Does it happen as I described? Can one use the BW command to actually compensate? Does it occur in USB only?
Thanks for any insight.
73's Tom

On Sep 22, 2014 7:25 PM, Don Wilhelm <[hidden email]> wrote:

>
> Tom,
>
> I don't know the answer, but what I can inject is the fact that the KX3
> shifts to Weaver demodulation at some point, it may be at 1.7 kHz.
> That would affect the signal peaks without substantially changing the
> sound of the signal on the KX3.
>
> 73,
> Don W3FPR
>
> On 9/22/2014 7:13 PM, [hidden email] wrote:
> > Hello,I received reports recently about the signal peaks that are seen in software based panadapters appear to shift by approximately 1.25kHz when the bandwidth control is changed from 1.8 to 1.7. in USB mode on the K3
> >
> >
> > At 1.8 the IS command returns 1500 in USB and the BW command returns BW0180
> > AT 1.7 the IS command returns 1500 in USB and the BW command returns BW0170 which is normal behavior.
> >
> >
> > I have investigated this and it indeed happens when the bandwidth is changed from 1.8 to 1.7
> > The sound of the signal nor the tuning of the radio is changed. However, a QSY to the original peak will detune the signal.
> > This has been confirmed in Win4K3Suite, NAP3 and HDSDR.
> >
> >
> > Can someone check this please on the PX3?
> > This is on the latest firmware of 2.19
> >
> >
> > Thanks, Tom va2fsq
> >
>

Don Wilhelm-4

Re: KX3: Is this a serious error in KX3 Firmware affecting the IQ output?

Tom,

Look up Weaver demodulation on the web and you will see that when that
demodulation technique is used, there will be content in the low
frequency portion of the audio and aalso on the high end, with little
signal in the middle of the audio spectrum.
It should happen in both LSB and USB, and I believe the starting point
is for a bandwidth of less than 1.8 kHz.

It seems to me that the 'center of the passband' should be about halfway
between the two peaks, but a closer study of Weaver demodulation may
give you a better clue to deciding how it should be displayed.

73,
Don W3FPR

On 9/22/2014 7:50 PM, Tom Blahovici wrote:

> Hi
> If this is the case is there any way to determine exactly where or when this happens? Does it happen as I described? Can one use the BW command to actually compensate? Does it occur in USB only?
> Thanks for any insight.
> 73's Tom
>
> On Sep 22, 2014 7:25 PM, Don Wilhelm <[hidden email]> wrote:
>> Tom,
>>
>> I don't know the answer, but what I can inject is the fact that the KX3
>> shifts to Weaver demodulation at some point, it may be at 1.7 kHz.
>> That would affect the signal peaks without substantially changing the
>> sound of the signal on the KX3.
>>
>> 73,
>> Don W3FPR
>>
>> On 9/22/2014 7:13 PM, [hidden email] wrote:
>>> Hello,I received reports recently about the signal peaks that are seen in software based panadapters appear to shift by approximately 1.25kHz when the bandwidth control is changed from 1.8 to 1.7. in USB mode on the K3
>>>
>>>
>>> At 1.8 the IS command returns 1500 in USB and the BW command returns BW0180
>>> AT 1.7 the IS command returns 1500 in USB and the BW command returns BW0170 which is normal behavior.
>>>
>>>
>>> I have investigated this and it indeed happens when the bandwidth is changed from 1.8 to 1.7
>>> The sound of the signal nor the tuning of the radio is changed. However, a QSY to the original peak will detune the signal.
>>> This has been confirmed in Win4K3Suite, NAP3 and HDSDR.
>>>
>>>
>>> Can someone check this please on the PX3?
>>> This is on the latest firmware of 2.19
>>>
>>>
>>> Thanks, Tom va2fsq
>>>

Don Wilhelm-4

Re: KX3: Is this a serious error in KX3 Firmware affecting the IQ output?

In reply to this post by tomb18

Tom,

There is another thing to consider, and that is whether the operator is
using Shift and Width to control the bandwidth or whether he is using
HiCut and LoCut.
If using Shift and Width, the center frequency would remain the same as
the Width is changed.
In HiCut/LoCut the center frequency will change with those settings.
The use of HiCut/LoCut for SSB is easier than trying to use Shift/Width
because not too much can be cut from the low end if signal
intelligibility is to be maintained, yet the high frequency end can be
cut substantially and still maintain intelligibility (even though much
of the individual voice characteristics will disappear. There does need
to be some content in the 400 to 500 Hz part of the audio spectrum for
the voice to be intelligible.

73,
Don W3FPR

On 9/22/2014 7:50 PM, Tom Blahovici wrote:

tomb18

Re: KX3: Is this a serious error in KX3 Firmware affecting the IQ output?

In reply to this post by tomb18

Hi Don,
Thanks for the info. I wish this was documented somewhere or perhaps I missed it. But it seems that so did all the other software developers making pan adopters for the kx3.
Perhaps someone from Elecraft could explain this and at exactly what point it occurs?
Thanks again.

On Sep 22, 2014 8:57 PM, Don Wilhelm <[hidden email]> wrote:

>
> Tom,
>
> There is another thing to consider, and that is whether the operator is
> using Shift and Width to control the bandwidth or whether he is using
> HiCut and LoCut.
> If using Shift and Width, the center frequency would remain the same as
> the Width is changed.
> In HiCut/LoCut the center frequency will change with those settings.
> The use of HiCut/LoCut for SSB is easier than trying to use Shift/Width
> because not too much can be cut from the low end if signal
> intelligibility is to be maintained, yet the high frequency end can be
> cut substantially and still maintain intelligibility (even though much
> of the individual voice characteristics will disappear. There does need
> to be some content in the 400 to 500 Hz part of the audio spectrum for
> the voice to be intelligible.
>
> 73,
> Don W3FPR
>
> On 9/22/2014 7:50 PM, Tom Blahovici wrote:
> > Hi
> > If this is the case is there any way to determine exactly where or when this happens? Does it happen as I described? Can one use the BW command to actually compensate? Does it occur in USB only?
> > Thanks for any insight.
> > 73's Tom
> >
> > On Sep 22, 2014 7:25 PM, Don Wilhelm <[hidden email]> wrote:
> >> Tom,
> >>
> >> I don't know the answer, but what I can inject is the fact that the KX3
> >> shifts to Weaver demodulation at some point, it may be at 1.7 kHz.
> >> That would affect the signal peaks without substantially changing the
> >> sound of the signal on the KX3.
> >>
> >> 73,
> >> Don W3FPR
> >>
> >> On 9/22/2014 7:13 PM, [hidden email] wrote:
> >>> Hello,I received reports recently about the signal peaks that are seen in software based panadapters appear to shift by approximately 1.25kHz when the bandwidth control is changed from 1.8 to 1.7. in USB mode on the K3
> >>>
> >>>
> >>> At 1.8 the IS command returns 1500 in USB and the BW command returns BW0180
> >>> AT 1.7 the IS command returns 1500 in USB and the BW command returns BW0170 which is normal behavior.
> >>>
> >>>
> >>> I have investigated this and it indeed happens when the bandwidth is changed from 1.8 to 1.7
> >>> The sound of the signal nor the tuning of the radio is changed. However, a QSY to the original peak will detune the signal.
> >>> This has been confirmed in Win4K3Suite, NAP3 and HDSDR.
> >>>
> >>>
> >>> Can someone check this please on the PX3?
> >>> This is on the latest firmware of 2.19
> >>>
> >>>
> >>> Thanks, Tom va2fsq
> >>>
>