All OB (Ortsbatterie Betrieb) WW2 German field telephones, including the Feldfernsprecher 33 (FF33), used a crank magneto for ringing. Learn about the most common types of OB WW2 German field telephones by reading my book. The 225 page book is available for $44.99 though the Lulu website at:
WW2 German Field Telephone Equipment 