Artificial Plate Battery
Plate batteries for old tube radios are today only available with difficulty. However, step-up controllers for low DC voltages are everywhere. The circuits of these IC’s are, however, affected by disadvantages and complex wound inductances are needed. A further disadvantage of this solution is the transducer frequency; poor placing can cause audible interference.
   Artificial Plate Battery
at www.zenithtrans-oceanic.portabletubes.co.uk