The amplitude modulation medium wave frequency range is 400khz-1650kHz, including 465kHz medium frequency. Short wave frequency range: 5mhz-18mhz.   Regarding the transmission distance, the transmission distance of the AM medium band is about 2 meters, while the transmission distance of the short wave and FM bands is about 10 meters. The distance is only for reference. Experimental FM and AM transmitter This is an experimental small household wireless transmitter that can transmit audio signals such as mobile phones through this transmitter and receive them with a regular radio. It can be used as an external microphone for small wireless microphones. This machine has three or four frequencies that can be transmitted. They are 90M, 105M, 12M, and 1000KHz, respectively. You can choose to transmit at any one of multiple frequencies. The launch distance is about 10-20 meters. This machine can serve as a reference for electronic enthusiasts to learn about wireless transmission.