[Elecraft] Triggering KPA500 from 2 Radios

[David Inger]

I have been using my K3/KPA500 setup for quite sometime.  I am using the
standard cable between the K3 ACC port and the KPA500 AUX for communications
between the radio and the amp.  This has worked perfectly from the
beginning.  At some time in the past, I wanted to use my Yaesu MKV Field to
excite the amp.  I connected both radios tho the KPA500 through a 2-position
coax switch.  I also connect a cable from the MKV  to the KPA PA. KEY jack.
When I switched the amp from standby to operate, there was a huge
attenuation of the MKV's received signal.  When I unplugged the K3-KPA AUX
cable the problem went away.  The received signal level was fine and the amp
produced +/-500 watts with about 40 watts of drive from the MKV.  An earlier
message on the reflector indicated that this signal attenuation with the AUX
cable connected was likely due to voltage signals on the AUX lines.  I
remove the MKV from the system and forgot about.
 
Well, I've rearranged my operating desk and would like to use the MKV a
little; I sure do like operating "the old monster"!  Next to the K3 it is
the best radio I have had on the desk.  So, back to the amp issue.  Has
anyone connected two radios--one being a K3 using the AUX cable--to the
KPA500, without having to plug/unplug cables to get everything to play
nicely?
 
73 de K6SBA
David in Santa Barbara, CA