[Elecraft] K3 Key Out Jack Not Working

[N4ZR]

I'm trying to set things up so that I can disconnect my 160M transmit 
antenna whenever I'm receiving, to prevent noise coupling into my RX 
antenna.  My thought is to use the Key Out jack on the K3 to control DC 
to a relay at the base of the antenna,  floating the base of the 
inverted L unless PTT is asserted.  The lashup is complete, and works 
when I short the phono plug manually, but not when I plug it into the 
KEY OUT jack and energize PTT.

I'm hoping it's just a menu issue, but my manual doesn't show any menu 
options affecting the Key Out Jack.  I have a KPA-1500, and Low Power 
Key Out via the ACConnector works fine for controlling the amplifier, so 
I assume the basic functionality is OK.  Any advice?  I'd really love to 
get it going for the Stew tomorrow!

-- 

73, Pete N4ZR
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