A Mini AM Radio Transmitter Kit
Radio News Stateside
Here is a link to a video demonstrating the AMT-MW207. This is a tiny US$25 mediumwave transmitter kit. It is described as follows: “The AMT-MW207 medium wave transmitter is a simple AM signal source suitable for amateur electronics enthusiasts and radio enthusiasts. It uses a magnetic rod to transmit electromagnetic waves without an external antenna.
It can be used to test ordinary medium wave radios in places where the radio signal is insufficient. As well as for radios, it can be used as an instrument for debugging medium wave radios […].”
It may be purchased on AliExpress:
(Source: SWLing Post | via Frans Goddijn)