K3EXREF problem

[wa9fvp]

I just installed the K3EXREF option and followed the step-by-step instructions.   I'm feeding it with a +10dbm level from my HP Z3801 disciplined, 10MHz reference.  The K3 doesn't appear to be locked.  The Installation and Operation manual says that "LOCKED will appear if you try to adjust the VFO A knob" but that doesn't happen.  Checking the frequency with WWV by using another radio in AM mode and comparing it to the K3, I can hear a beat note.

Jack WA9FVP
Willco Electronics