[Elecraft] help configuring the sub receiver

[Bruce McLaughlin]

A couple of days ago I received my K-3 back from Elecraft after having the
sub receiver and a few other accessories installed.  Unfortunately, the sub
receiver does not appear to work. I'm sure it's something dumb that I am
overlooking in configuring it.

Basically, I hear no signals.  I do hear what appears to be band noise but
nothing else.  This is on 40 meters during the daytime.  I have the
configuration set to what I believe is the atu unit.  I have only one
antenna which is connected to the main antenna 1 connector.  The sub
receiver sounds as though it has no antenna connected to it.  The other
choice available on the configuration menu appears to be to connect the sub
receiver to the BNC connector which appears to be an auxiliary antenna input
which I do not want to use since nothing is connected there.  I have both
the AF and RF gain controls for the sub receiver turned up full.

Can anyone suggest what I may be doing wrong?  I want to use the sub
receiver so that is connected to the same antenna as the main receiver and
transmitter, both of which run through the ATU.  I tuned the sub receiver to
the same frequency as the main receiver which had a very strong sideband
signal and should have been clearly audible by the sub receiver but there
was absolutely nothing other than some background hiss.  I will appreciate
any suggestions.

Bruce-W8FU