[Ron Ramirez]

Wire positioning is the first thing that comes to my mind. Assuming you have recapped the set, are the new capacitors in the same position as the originals? Was the position of the wires disturbed significantly?

There should be a wire connected to one top terminal of the tuning condenser, and wrapped around the other terminal (not connected). Is this wire in place? Although, I don't think this would cause howling.