[Elecraft] Data Mode Sideband

[David Cole]

Hi,
Please DO NOT take this discussion off list...  Or if you do, please
include me in the loop.  I find this most interesting.
-- 
Thanks and 73's,
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On Sun, 2014-08-24 at 09:49 -0300, 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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