[Elecraft] Data Mode Sideband

[Joe Subich, W4TV]

Mike,

> Important note: I run MMTTY in Logger32 which doesn't present the
> MMTTY UI quite the same as native MMTTY. What I attribute to MMTTY is
> likely a consequence of the way Logger32 talks to MMTTY.

More than likely it is not MMTTY that is doing the display frequency
manipulating but the Logger32 Digital interface code.

The native MMTTY interface will correct for USB operation.  In USB one
selects REV in the display and MMTTY will correctly use MARK + Shift
for internal frequency calculations.

Last time I checked the Logger32 "Display frequency from Radio" option
in the Sound Card Data Window as dumb - it did not understand that the
K3 and most Yaesu radios could report "Mark" frequency in AFSK - and
simply added (AFSK) or subtracted (AFSK-R) MMTTY's MARK frequency from
the reported radio frequency.  This results in incorrect display for
two reasons - 1) with the K3 it is applying an offset that is already
applied in the reported frequency, 2) the offset is applied in the
wrong direction since Logger32 always assumes AFSK (audio) is USB.

Logger32 has had the same brain dead interface for the Sound Card Data
Window for perhaps 10 years.  It did not work correctly with the Yaesu
FT-1000D/MP/MKV and still does not work correctly with the K3.

None of this absolves the K3/and P3 of one mistake.  The P3 frequency
cursor (and K3 frequency display) appear to show the SPACE frequency
in AFSK R (and FSK R) - perhaps they are really "reverse" as opposed
to "opposite sideband" <G>.

73,

    ... Joe, W4TV


On 2014-08-24 8:49 AM, Mike Harris wrote:
> Hi Don,
>
> I've made thousands of RTTY QSOs.  I know what I'm doing.
>
> Pondering the problem further I now believe that AFSK A and AFSK A Rev
> are similar in operation to CW and CW Rev.  Theoretically the decode
> will (should) stay correctly tuned as the "suppressed carrier" is
> shifted to suit.  The handbook offers no clarification on this.
>
> Important note: I run MMTTY in Logger32 which doesn't present the MMTTY
> UI quite the same as native MMTTY.  What I attribute to MMTTY is likely
> a consequence of the way Logger32 talks to MMTTY.
>
> The situation, which actually is of no consequence, is that MMTTY or
> whatever doesn't understand the frequency manipulations that the K3
> performs with respect to VFO display vs mode.  The K3 reported frequency
> via the IF; command is interpreted as the suppressed carrier frequency,
> which it isn't.  ALT is responded to as a sideband change, which it
> isn't in conventional terms eg switching sidebands in SSB because of
> additional frequency manipulation in the K3.
>
> The consequences are that the RTTY frequency MMTTY displays is incorrect
> and hence any logging info produced would also be incorrect.  This could
> also be an issue with other data applications.  I don't run any others
> so that is for others to determine.
>
> Now in my circumstance as I have said it is of no consequence.  Logger32
> correctly logs the displayed frequency from the K3 as reported by IF;. I
> simply ignore any frequency displays that this implementation of MMTTY
> presents.
>
> The reason for trying to get a detailed handle on what was happening was
> to see if it was possible to somehow, through a radio profile or other
> means, to bring everything into line without too much effort.
>
> Regards,
>
> Mike VP8NO
>
> On 23/08/2014 16:50, Don Wilhelm wrote:
>> Mike,
>>
>> Do you have MMTTY set for 1445Hz Mark *and* the K3.  Hold PITCH button
>> to check/change.
>> That would make a difference in AFSK A, but not in DATA A mode
>>
>> 73,
>> Don W3FPR
>>
>> On 8/23/2014 3:00 PM, Mike Harris wrote:
>>> Not so sure.  I monitored the TX frequency on another RX and the only
>>> change was the slight shift I mentioned, not what would, in my case
>>> (1445Hz Mark) be approx 3kHz.
>>>
>>> Using DATA A, which really does swap sideband results in a near 3k
>>> frequency shift.
>>>
>>> Regards,
>>>
>>> Mike VP8NO
>>>
>>> On 23/08/2014 15:27, Joe Subich, W4TV wrote:
>>>>
>>>>> Mode AFSK A normal LSB. I assumed that if by using the ALT function
>>>>> and consequently switching to TX DATA REV that the sideband was
>>>>> switched from LSB to USB.
>>>>
>>>> It is.
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