Re: K3: Passband Offsets per Mode

[Richard Ferch]

Jim,

You need to separate what your software is doing from what the radio is
doing.

If you turn the radio on without using any radio control software, and
if after changing modes you press and hold the SHIFT button, the radio
will change to its default (NOR) filter settings in that mode. The
defaults are (or at least, this is what they are on my radio):
SSB: 0.15 kHz to 2.85 kHz
CW: PITCH - 0.2 kHz to PITCH + 0.2 kHz
DATA A: 1.3 kHz to 1.7 kHz
AFSK A and FSK D: PITCH - 0.2 kHz to PITCH + 0.2 kHz
Note that the PITCH settings in CW and in RTTY (AFSK A/FSK D) are separate.

Evidently the default bandwidth in CW and DATA modes is 0.4 kHz, and in
SSB it is 2.7 kHz. The default centre frequency is the selected PITCH in
CW and RTTY modes, and 1.5 kHz in SSB and DATA A.

If you change any of the shift/width or lo/hi cut settings, the radio
will remember the changed settings on a per-mode basis. The remembered
settings persist through power on-off cycles; turning the power off and
on does not restore the defaults. If you change the bandpass settings in
one mode, that change will have no effect on other modes. All four DATA
sub-modes change width and offset from the default centre frequency
together, although the default centre frequency changes between
sub-modes. (Actually there are two remembered settings per mode,
labelled I and II - see the Owner's Manual for details.)

If you set everything back to the defaults, turn your control software
on and change modes from the software, and you discover that the
resulting bandpass settings are different from the defaults, that tells
you that the software must have sent commands to the radio to select
bandpass settings different from the radio's defaults. In that case, you
would have to ask the software developers why they chose the particular
settings they did.

73,
Rich VE3KI
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

[Jim Rogers, W4ATK]

Rich, you win the prize..... Exactly and that is a scenario that in my  
transition from the FT2000 to the K3 that I was having trouble with.  
If I have tuned to a signal on 7.1MHz, that signal will be in the  
center of the selected filter.  DM-780 was telling me it was 1.5 +/-  
kHz away.

When I would shift the IF to receive say a lower frequency signal in  
the waterfall of DM-780 then I would be out of the pass band of the  
filter and PANIC!, no power out.

I just knew there was an explanation sitting right there before me,  
but for some reason just could not quite get there. Actually, Gary at  
Elecraft called right before I read your e-mail and after he and I  
walked through somethings, we got on the same page and it is all  
resolved.

Fantastic support as always from Elecraft and its users.

73s and thanks to all who responded, Jim, W4ATK (Could we chalk this  
up to my being 77 today?)


On Sep 21, 2010, at 12:22 PM, Richard Ferch wrote:

> Jim,
>
> You need to separate what your software is doing from what the radio  
> is
> doing.
>
> If you turn the radio on without using any radio control software, and
> if after changing modes you press and hold the SHIFT button, the radio
> will change to its default (NOR) filter settings in that mode. The
> defaults are (or at least, this is what they are on my radio):
> SSB: 0.15 kHz to 2.85 kHz
> CW: PITCH - 0.2 kHz to PITCH + 0.2 kHz
> DATA A: 1.3 kHz to 1.7 kHz
> AFSK A and FSK D: PITCH - 0.2 kHz to PITCH + 0.2 kHz
> Note that the PITCH settings in CW and in RTTY (AFSK A/FSK D) are  
> separate.
>
> Evidently the default bandwidth in CW and DATA modes is 0.4 kHz, and  
> in
> SSB it is 2.7 kHz. The default centre frequency is the selected  
> PITCH in
> CW and RTTY modes, and 1.5 kHz in SSB and DATA A.
>
> If you change any of the shift/width or lo/hi cut settings, the radio
> will remember the changed settings on a per-mode basis. The remembered
> settings persist through power on-off cycles; turning the power off  
> and
> on does not restore the defaults. If you change the bandpass  
> settings in
> one mode, that change will have no effect on other modes. All four  
> DATA
> sub-modes change width and offset from the default centre frequency
> together, although the default centre frequency changes between
> sub-modes. (Actually there are two remembered settings per mode,
> labelled I and II - see the Owner's Manual for details.)
>
> If you set everything back to the defaults, turn your control software
> on and change modes from the software, and you discover that the
> resulting bandpass settings are different from the defaults, that  
> tells
> you that the software must have sent commands to the radio to select
> bandpass settings different from the radio's defaults. In that case,  
> you
> would have to ask the software developers why they chose the  
> particular
> settings they did.
>
> 73,
> Rich VE3KI
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

[K4SC]

Rich;

I copied your reply verbatim and pasted it into a text file.  The file now resides in my K3 folder along with the Operating Manual and other important K3 info.  I put it there because I know this information will be invaluable some late night.

Thanks!