FT8 DXpedition Mode test.

[Stephen Shearer]

 1.   I had fun.
 2.   I read the Guide before, during, and after the test.
 3.   I started to 20m and was confused.  Partly because I was not
    hearing the FOX and was seeing stations below 1K with "R-12" reports.
 4. On 20m, it did not help that XE1GK was calling CQ on top of W1/KH7Z
    +/- 1HZ (I did see KH7Z a few times with reports).  Being in W3 I
    would not "expect" to hear a W1, but the XE1 was -1 to -15 didn't help.
 5.   I saw CQ on 30m.  Since I could see both sides of the QSO, I was
    "starting" to figure out the change in freq to below 1K.
 6.   On 30m, now that I was calling, I figured out the Split Operation
    Rig/Fake It set-up.  I changed to "Rig".
 7.   On 30m, I realized, now that I could "see" the FOX that my RX
    bandpass did not cover 300Hz.
 8.   My KX3 with "Data A" has a wide bandpass of 400Hz to 3500Hz and
    shifting the RX down was not going to work with the software shift
    for the report, I "guess"...
 9.   I changed my KX3 to USB, removed CMP and RX/TX audio EQ.  The
    lower RX cut-off would receive the FOX on the assigned freq.
10.   I looked at the KX3 manual C5 for a way to set the passband low
    end cutoff while in Data A mode.  Nothing found.  Does the K3s have
    the same problem?
11.   On 40m, I now knew what was going on...  I heard the CQ, The FOX
    answered my GRID and the software moved me between 300Hz and 900HZ
    (the manual does say that) but until it happens, I was not sure what
    it meant. The FOX never "RR73" 'd me.  I was running 10 watts.
12.   On 80m it was the same as 40m.  I was running 15w (with a fan
    blowing on the heatsink).  I never finished a QSO.
13.   I had fun and thank you for the DXpedition effort.
14.   I need to see what Elecraft has to say about the "Data A" low freq
    cut-off setting...


73, steve WB3LGC

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[Don Wilhelm]

Stephen,

In DATA A, use the SHIFT (PBT II) to shift the passband down.
The widest passband is 3000 Hz. which is consistent with your 400 to
3500 Hz observation.  I suggest shifting it to 150 to 3150 Hz.  It will
work fine for most soundcard data modes.

The K3/K3S has the same behavior, but it is not a problem.

73,
Don W3FPR

On 3/7/2018 11:47 AM, Stephen Shearer wrote:
>
> 8.   My KX3 with "Data A" has a wide bandpass of 400Hz to 3500Hz and
>     shifting the RX down was not going to work with the software shift
>     for the report, I "guess"...
> 9.   I changed my KX3 to USB, removed CMP and RX/TX audio EQ.  The
>     lower RX cut-off would receive the FOX on the assigned freq.
> 10.   I looked at the KX3 manual C5 for a way to set the passband low
>     end cutoff while in Data A mode.  Nothing found.  Does the K3s have
>     the same problem?
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[Stephen Shearer]

Don, OK I had to test this again and look at the manual.  I "thought" I
tried shift but brain cells are getting old...

I used fldigi to see a nice 0-4K audio spectrum.
I went to 40m (shouldn't matter), set DATA A, set BW=4.0, Adjusted FC
from low to high 1.28 to 1.64 with *1.5.
     FC ... If I change it over its full range the lowest it goes is
375HZ (and that may be 10dB down?).
     If I change BW=3.0, same but High end varies.
     With BW=4.0, only high end varies.
     If I make BW=1.7, I can move low end up but not below the ~400HZ...

I have latest firmware, MCU 02.90 DSP 01.52

If I use USB...  BW=4.0 FC=*1.5  I have an audio range from 200Hz to
3500Hz ??
I even went back and zeroed my RX EQ.
I guess I can't use DATA A with FT8 in DXpedition Mode.
It won't matter with other modes as only DXpedition mode needs RX at
300Hz...
And I may have been the only one using a KX3 for the test?
*I think the answer is that the problem is not **with me, its firmware
limits...*

The WSJT-X software does other "tricks" to move the TX freq keeping it
within the TX bandpass, 1500Hz +/- 500Hz (it looked like...)  Note, not
relative to "issue", just info.


BTW, thanks for all you do for the Elecraft community!

73, Steve WB3LGC


On 3/7/2018 1:42 PM, Don Wilhelm wrote:

> Stephen,
>
> In DATA A, use the SHIFT (PBT II) to shift the passband down.
> The widest passband is 3000 Hz. which is consistent with your 400 to
> 3500 Hz observation.  I suggest shifting it to 150 to 3150 Hz. It will
> work fine for most soundcard data modes.
>
> The K3/K3S has the same behavior, but it is not a problem.
>
> 73,
> Don W3FPR
>
> On 3/7/2018 11:47 AM, Stephen Shearer wrote:
>>
>> 8.   My KX3 with "Data A" has a wide bandpass of 400Hz to 3500Hz and
>>     shifting the RX down was not going to work with the software shift
>>     for the report, I "guess"...
>> 9.   I changed my KX3 to USB, removed CMP and RX/TX audio EQ. The
>>     lower RX cut-off would receive the FOX on the assigned freq.
>> 10.   I looked at the KX3 manual C5 for a way to set the passband low
>>     end cutoff while in Data A mode.  Nothing found.  Does the K3s have
>>     the same problem?
>

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