[Elecraft] Fwd: KPA500: strange behaviour - resolved.

[zendoc at netspace.net.au]

Hi All,

Just to close the loop, a note to say that I found the cause of this intermittent issue: I removed the adapter cable between the PC and the KPA500 and the issue has not recurred after many hours of use. I suspect it related to some RF getting in to the control circuits of the amp via the cable, as one poster suggested. Thanks to everyone for the replies and ideas.

73,
John
VK7JB

> 
> I'm running KPA500 #1076 with firmware 1.23 installed.  It's connected to my K3 via the elecraft AUX cable and is connected to my PC via serial to USB adapter cable using FTDI chipset.  Interfacing functions with the PC and K3 work flawlessly.
> 
> It runs perfectly apart from one intermittent peculiarity:  unpredictably, when in QSO, the amp will switch from operate to standby mode.  This does not trigger the Fault indicator and no fault # is ever reported by the KPA500 to the utility program or to the K3 LCD.  It can't identify any triggers for these auto-tripping events. I simply return the KPA500 to operate mode and continue the QSO normally.  This occurs on average once per hour of operation, rarely 
>