[Elecraft] KX3 Data A and AFSK-A Mode need help

Richard Ferch ve3iay at storm.ca
Tue Jun 11 19:26:53 EDT 2013


Actually, Don, DATA A is upper sideband. AFSK A and FSK D are lower 
sideband.

I believe the problem is that MixW (or some versions of MixW, at least) 
treats all of the K3's data modes are the same; I believe it treats them 
the same as the Kenwood FSK mode, i.e. as lower sideband. This would 
work correctly with AFSK A and FSK D, but not with DATA A. Switching to 
DATA A-REV would not help, because MixW would then think the radio is in 
USB (Kenwood's FSK-R) when it is actually in lower sideband. When the K3 
is in USB (voice mode) as distinct from DATA A, MixW gets it right.

You can always force MixW to use the correct sideband by changing its 
sideband control from Auto to manual control: USB or LSB, depending on 
which sub-mode you are using.

There is another potential problem with data modes as well, and that is 
accurate reporting of frequencies. In AFSK A and FSK D, the K3 dial 
displays the mark frequency, in agreement with standard amateur 
convention. My recollection is that MixW expects this, in agreement with 
the Kenwood FSK mode. Apart from a possible 85 Hz offset (I believe MixW 
logs the center frequency, not the mark frequency), this is correct in 
the K3's AFSK A and FSK D, but incorrect in DATA A, where the correct 
frequency is found by adding the audio mark pitch to the displayed 
(suppressed carrier) frequency (as in USB).

MixW is not the only program that has trouble with the K3's data modes. 
I believe Fldigi has similar problems. Using RigCAT, depending on what 
is in your rig control .xml file you can persuade Fldigi to treat the 
K3's data modes either as USB (correct for DATA A) or as LSB (correct 
for AFSK A), but not both. I believe there may be similar problems with 
frequency offsets (correct either for DATA A or for AFSK A, but not for 
both).

As for MMTTY, it assumes the radio is in lower sideband (correct for FSK 
D and AFSK A). If you use DATA A with MMTTY, you have to press MMTTY's 
Reverse button. You can also tell MMTTY whether to use a frequency 
offset (yes for DATA A, no for FSK D and AFSK A).

N1MM Logger understands the K3's various data submodes correctly as far 
as the sideband is concerned, but you still have to control whether or 
not it applies an offset by using a configuration switch.

73,
Rich VE3KI


Don W3FPR wrote:

> Franco,
>
> Have you tried setting MixW to RTTY normal and setting the K3 DATA A
> mode to reverse?  DATA A is normally LSB, if you hold ALT (left side of
> MODE button) it will go to USB.
>
> 73,
> Don W3FPR
>
> On 6/11/2013 12:02 PM, IZ4MJP.com wrote:
>> Hello Mat.
>> Many thanks for the answer.
>>
>> I've already tried with RTTY-R but with no luck. In USB Mode or ASFK A no problem \
>> at all with the same settings.
>> I'll give a try using MMTTY (maybe MixW 3.xx doesn't love DATA-A, hi hi).
>>
>>



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