[Elecraft] What is actually present on Rx-Out BNC of the KXV3 RF bosrd??

[Bob KD7YZ]

I bought a Fucubr Donglr Pro+ AKA FCDP+ or FC+ .
The USB device has a connector to which, via adapter(s), one can connect
any antenna we all own.

So I want whatever antenna the K3 is currently using to let signals from
that antenna, in the Rx mode only, to be present on Rx-Out BNC, on the
back of my K3.

I thought I was perhaps "there" except that the signals appearing on a
waterfall display, of SDR-Radio  program, were all but reduced to 0 they
were so very very weak.

Is there another adjustment, in the CONFIG, I need to make?

-- 

Bob KD7YZ
http://www.qrz.com/db/KD7YZ
www.denstarfarm.us/LGD