WESTERN ELECTRIC COPPER OXIDE RECTIFIER BOX J86205H L1

[unbeldi]

Thanks for the eBay link!   As hoped, that solved the 'puzzle' about the circuit.

Here it is ... if anyone is still listening.

Turns out the unit only supplies transmitter current to ONE phone, but they needed both coil assemblies for very thorough AC filtering along-side the huge electrolytic capacitor.

This capacitor probably needs special attention before operating this unit again. The label contains a specification that instructs to operate the unit for one hour at least every 18 months.

Now that I know how this thing works,  I would use it only for display.  I can supply 3 and 25 volts much more efficiently without all that loss of energy.

Oh, the box actually sold for $104, a late sniper came to sweep it.  Seems rather stiff, wow.