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.

它本来是被用作调收音机中本振和混管，并且被大量生产出来以实现这个用途。

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 ...

等磁场磁感应强随源输出增加而增加,磁场调处理能提磁场内磁感应强,提调波信号值压,可有效提磁场内磁感应强。