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.

它本来是调收音机中的本振和混频管，并且大量的生产出来以实现这个途。

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源输出流的增加而增加,磁场调处理能提高磁场内的磁感应强,提高调波信号的压,可有效提高磁场内的磁感应强。