Does anyone here know the catalog and/or part number for the Sola Constant Voltage Filament Transformer used in the original Fairchild 670? I came across a Sola in my shop that looks like the one in gunshot photos of the 670. It is Cat. No. 20-02-015, 95 to 130v in, 6.3v out. I understand these are known to fail so if I have the right part I figure I probably ought to get it into the hands of an original 670 owner. Thanks.