[Elecraft] P3 spurious display

[Alan Bloom]

Craig,

Yes, this is a known bug that will require a K3 firmware change.  When
using semi break-in CW the P3 does not "mute" properly on transmit so
you are seeing the transmit IF signal.  It's on the list.

Alan N1AL


On Fri, 2011-01-14 at 08:06 -0700, Craig D. Smith wrote:
> To avoid confusion, please note that this posting is not about the recent
> 0.50 firmware upgrade, but rather behavior with the previous release-level
> version.
> 
> I'm experiencing some curious behavior from the P3 on CW that perhaps some
> of you can help explain.  Certainly not a show-stopper, but sometimes mildly
> annoying.
> 
> I notice this mainly during contests when I'm using my contest program to
> key the K3 via the KEY input.  I see a spurious signal displayed on the P3
> that is 800 Hz above my xmit frequency.  At first, I thought this was an
> actual signal, but soon realized it was some kind of display artifact from
> keying the K3.  It looks like a regular CW signal, and has a maximum
> amplitude of about -80 dBm.  It seems to be generated during closures of the
> KEY input to the K3.  It appears to be independent of power level or the CW
> pitch frequency.  Same result using antenna or dummy load.
> 
> This is MUCH less of a problem when using the internal K3 keyer via the
> PADDLE inputs.  If I hold down the paddle to generate a string of dits, the
> P3 display freezes at the baseline noise level and the spurious indication
> does not appear.  On the other hand, if I generate a series of dits with the
> paddle by making a sequence of rapid contact closures of the dit paddle, the
> spurious P3 indication does appear.
> 
> In other words, it appears to have something to do with how the K3/P3
> handles the "freezing" of the P3 display during CW transmit, especially in
> the event of rapid keying contact closures.
> 
> Any ideas?
> 
> Thanks and 73      Craig   AC0DS
> 
> 
> 
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