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

[Don Wilhelm]

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 <w3fpr at embarqmail.com> 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, tomb18 at videotron.ca 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
>>>