Its purpose in life was to be the local oscillator and mixer in AM radios, and a kazillion of them were made to fill that purpose.

它本是被用作调收音机中的本振和混频管，并且被大量的生以实现这个用途。

The maximum of B along elevation direction is closely under the central section of coil.The B of equiamplitude magnetic field is increased by increasing of the output current ...

等高频磁场的磁感应强随高频电源输电流的增加而增加,磁场调能提高磁场内的磁感应强,提高调波信号的值电压,可有效提高磁场内的磁感应强。