[Elecraft] Data Mode Sideband

[Mike Harris]

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.