细节
A B.T.H. twin crystal wireless receiver
type C form A, with instructions in the lid, twin enclosed crystal chamber and B.T.H. loading coil and type 640 condenser attachments -8½in (21.5cm) high
type C form A, with instructions in the lid, twin enclosed crystal chamber and B.T.H. loading coil and type 640 condenser attachments -8½in (21.5cm) high