[Elecraft] K3S Sub-Receiver: How to Hear Both Receivers?

[Byron Peebles]

Is there a way to have the signals on both the main and sub-receivers?

For example, listening to a DX operator who is running split.

I would like to hear the DX on the Main, and both Listen and Transmit on 
the Sub.

I've read and re-read a lot of pages, pressed a lot of button 
combinations, but have yet to hear any signals on the sub-receiver.  
When I A/B swap, I hear things on Main, but never on Sub.

I am new to the Elecraft style, so I might bemissing something obvious 
to others.

(100)-72, Byron