I made 2 mistakes in fixing my sb102 before I sold it.  First of all, I shorted out a ground lug associated with the plate current meter in the process of resoldering an af gain control.  I fixed that one by resoldering the wire to the meter and boy did the volume blow me out of the room hi hi.  Then I really understood what older handbooks were talking about with regard to safety when I was in the process of neutralizing an rf amplifier after I replaced the driver and two final tubes when I inadvertently came into contact with the secondary of the transformer with a screw driver in my hand.  Fortunately, I lived to tell about it because I had one hand in my pocket and I wasn't working alone.  73- pat kk3f