[Elecraft] KAT500 antenna port isolation

[ANDY DURBIN]

I've been using Alpha Delta model Delta-4 switches for manual antenna selection.  I thought that having the ability to auto select the appropriate antenna with my KAT500 would be a significant improvement for my station.  I don't have a K3 so I created a band decoder that drives the KAT500 band inputs and now have automatic antenna switching.  However, I'm unimpressed by the isolation between antenna ports.  

With the KAT500 switched to the dummy load I'm still decoding a local FT8 station on 6 m.  The difference in the FT8 signal between dummy load and antenna is about 19 dB.   I have not found a specification for KAT500 port isolation.  Is what I'm seeing typical?

Thanks and 73,
Andy k3wyc