[Elecraft] PX3 Anomaly

[Phil Wheeler]

Make sure those (all!) cables are fully inserted, 
Ted. I've found that to take more "push" in the 
case of the KX3 and PX3 than some of my other devices.

Phil W7OX

On 6/13/15 4:39 PM, Dauer, Edward wrote:
> Finally got the KX3 – PX3 – KXPA100 system cabled together and on the air
> today, all of the F/W updated.  All OK but for two anomalies, one of them
> a bit of a nuisance.
>   
>
> The PX3 shows a double sharp spike offset from the tuned frequency about
> 600 and 700 Hz (an eyeball estimate), at about S2.  The twin spikes just
> stay there a fixed offset away from the marker as the rest of the band
> marches by.  (The PX3 is in tracking mode – I haven’t downloaded the beta
> revision.)  Same thing on every band I’ve tried – 10, 15, 20 and 40.  Some
> other symptoms:
>   
>
> The small bit of spectrum (about 100 Hz) between the two spikes is devoid
> of signal – jet black even when the ref level is set so that the rest of
> the waterfall span is showing blue.
>   
>
> The spikes appear in CW mode but not in AM or SSB.  They switch sides when
> I switch cw sidebands – 600 and 700 Hz below center when the KX3 is in CW
> rev, and the same distance above center when it’s changed back.
>   
>
> When the i/Q cable is disconnected at either end, the spikes slowly
> decline.  But with the cable connected and the KX3 power turned off, they
> are still there on the PX3.
>   
>
> The spikes remain at 600 and 700 Hz offset from center regardless of the
> span setting.
>   
>
> Weird.  And troubling, because 300 - 600 Hz is a typical XIT offset I use
> in pileups when the DX isn’t working “up.”  Anyone have any ideas?  Anyone
> seen this before?
>   
>
> The other glitch is much less trouble.  The KX3 setting sometimes switches
> itself from PA Mode On to PA Mode off.  I think I’ve figured it out – if I
> turn the KXPA100 power off before turning the KX3 off, or if I turn the
> KX3 on before powering up the amp, the KX3 must be sensing “no amp” and so
> switching itself back to PA Mode Off.  But then when the amp comes on, the
> KX3 doesn’t sense that and switch back to PA Mode On. An intelligent
> default choice, maybe.  Any way to defeat it?
>   
>
>
> Ted, KN1CBR