[Elecraft] K3 - PR6-10 - KPA500 not working together

[Ken Kontor]

Help !

I just added a KPA500 to my K3, P3 setup.

I have an interface question / problem.

I connected the TX keying line connector to my K3, then the Y cable, 
then the AUX cable to my KPA500. I am using the key out from the K3 to 
the PA key jack on the KPA500. (All per Elecraft Manual). This seems to 
be working OK.

I also have a PR6-10 preamp connected to the K3 with the control wire 
going to the appropriate pin of a separate 15 pin plug and a low band 
receive antenna connected to the preamp in line. DIGOUT is set to ON for 
6m, 10m & 12m and OFF for all other bands. If I connect this plug to the 
ACC connector of the K3 by itself (no cable connected to the KPA500) it 
works as it should (preamp on for 6m, 10m, & 12m and off for the other 
bands) and the external receive ant for 160m works as it should.

When I connect this plug to the Y cable, it still works as it should, 
but when I add the AUX cable on the other half of the Y cable, the 
external receive antenna is disconnected, which seems to indicate that a 
signal from the KPA-500 is turning on the preamp and stopping the low 
band antenna from passing through. If I disconnect the AUX cable to the 
KPA500, everything reverts to working as ir should.

Any ideas as to how to make these two devices work together ???

Ken - W8KEN