[DaleHCook]

The needed transformer for this set would be anything out of any AA5 type of set.

Still, I would like to figure out which transformer is currently in it. It bugs me when I see a part number which seems familiar, but I can't find the manufacturer. Of course, it is possible that a previous owner replaced the original with one from a scrapped out AA5. That would certainly be true if "8-39" is a date.

On the subject of output transformer primary impedances, the stated plate impedance for a given type of tube will vary somewhat from manufacturer to manufacturer, and with various operating conditions. Plate impedance, however, is not the value which you want to use for the primary impedance of an output transformer when selecting a replacement. You want to use the load impedance shown in a receiving tube manual for the operating conditions which most closely match your set. When building my Universal Shop Speaker and Dummy Field Coil, I compiled a primary impedance table to help me to select which taps to use on the included universal output transformer, based upon tube type and operating conditions. It has primary impedance values averaged from the dozens of receiving tube manuals in my library.