[Elecraft] P3 span changing

[Alan Bloom]

If you return to a band but at a different K3 VFO frequency, the new 
frequency may be outside the P3's span.  If that happens, the P3 will 
re-tune using an algorithm determined by the MENU > FixMode setting.

If you want to be sure the P3 frequency doesn't change you can set 
FixMode to "Static".  Then the P3 frequency range will not change even 
if the K3 VFO frequency is out of range.

It may be that some logging programs do not retain the old frequency 
upon a band change.  Even if the frequency is "wrong" only for an 
instant, that would be enough to confuse the P3 if not in "Static" mode.

It would be interesting to see what N1MM and other logging programs are 
sending to the P3/K3 on band changes.  There is a little-known serial 
debug monitor in the P3 that shows the traffic on the two RS-232 ports.  
You activate the function by simultaneously holding the DISPLAY/AVERAGE 
and FN1/FN5 buttons.  The P3 screen changes to show RS-232 traffic 
color-coded to show on which port and in which direction the traffic is 
going.

The data can fly by awfully fast when using a logging program.  You can 
freeze the screen immediately after a band change by tapping the FN2 
key.  Tap it again to unfreeze the screen.  If you want to show more 
data you can choose a smaller font size with the MENU > Font feature.

I'm pretty sure that feature still exists in current P3 code.  I can't 
check this myself since all my ham equipment was recently lost in a fire.

Alan N1AL


On 2/8/2021 4:05 PM, Jim McDonald wrote:
> I use the Fixed Tune Mode too but the center frequency sometimes isn't remembered when returning to a previously-used band.  If it makes any difference, I'm usually using N1MM+ (often with Win4K3Suite) to control the radio.
>
> 73,  Jim N7US
>
> -----Original Message-----
> From: elecraft-bounces at mailman.qth.net <elecraft-bounces at mailman.qth.net> On Behalf Of Fred Jensen
> Sent: Monday, February 8, 2021 16:45
> To: elecraft at mailman.qth.net
> Subject: Re: [Elecraft] P3 span changing
>
> Don't understand your "follow option" question.  I run mine in Fixed Tune Mode which holds the span [i.e. edge frequencies] constant and the two VFO's show up as two vertical cursors in the spectrum display.  The cursors move as I tune, and when I go beyond the edge, the span shifts by the amount I've set in the menu ... I use a full span.  In the Tracking Mode, your receive frequency is always centered and the spectrum moves past it as you tune.
>
> 73,
>
> Fred ["Skip"] K6DGW
> Sparks NV DM09dn
> Washoe County
>
> On 2/8/2021 2:34 PM, Dave Cole wrote:
>> How does one set the follow option, I just looked through the menu of
>> the P3, and don't see it.
>>
>> 73, and thanks,
>> Dave (NK7Z)
>> https://www.nk7z.net
>> ARRL Volunteer Examiner
>> ARRL Technical Specialist, RFI
>> ARRL Asst. Director, NW Division, Technical Resources
>>
>> On 2/8/21 12:39 PM, Fred Jensen wrote:
>>> Yes, it has been discussed, and yes, that is the case.  It seems to
>>> be most prevalent when returning to a band after moving off for a Q,
>>> such as in NAQP's when the return is being commanded via CAT command.
>>> In fairness to the Elecraft developers, it /*appears*/ that it is
>>> attempting to put the frequency you are returning into the center-ish
>>> part of the display which is not totally unreasonable.
>>>
>>> 73,
>>>
>>> Fred ["Skip"] K6DGW
>>> Sparks NV DM09dn
>>> Washoe County
>>>
>>> On 2/7/2021 12:28 PM, Jim McDonald wrote:
>>>> I know this has been asked before but I don't remember the answer.
>>>> Isn't the P3 supposed to remember the span and center frequency from
>>>> band to band?  It seems to change center frequency even if the band
>>>> hasn't changed, but that may not be the case.
>>>>
>>>> 73,  Jim N7US