K3 VFO A and VFO B linked - Help

[Henry Pollock - K4TMC]

Getting ready for the CA QSO Party and discovered that the reliable old K3
#98 is sick. So pulled the spare K3 #5573 out of storage and started
checking it out.

I find that VFO A is somehow linked to VFO B, such that turning the main
knob controls both VFO A and VFO B. I can change VFO B separately with the
B knob.

There is no 2nd (SUB) receiver in the rig.  The general coverage board is
installed. Split is off.

Never had this problem with #98. What am I missing?

73,
Henry - K4TMC