The emitter is a simple AM signal source for amateur electronics and radio enthusiasts. It"s simple in circuit and easy to use. It uses common parts for easy to make. A volumepotentiometer with a switch can realize the modulation depth adjustment, which is the onoff function. The amplitude modulation frequency of the emitter is 600Khz-1500Khz, which can receive a maximum distance of about 5m. 3.5mm headphone jack for external o modulation signal. This emitter is used for debugging and maintenance of the radio, radio station, SDR receiver, and other assemblies of the tool. Features: Simple Circuit for Easy to Make: This kit is simple in circuit, it uses common parts for easy to make. A volumepotentiometer with a switch can realize the modulation depth adjustment, which is the onoff function.  Wide AM Frequency Ranges: The amplitude modulation frequency of the emitter is 600Khz-1500Khz. This emitter is a low-power emitter and can receive a maximum distance of about 5m.  High Sound Quality: The sound quality is close to FM broadcasting within the rated transmission distance, with a nice signal-to-noise ratio, especially since the effect of receiving through a repeater is not much different from that of direct transmission of modulated signals. The sound fidelity is higher. Easy to Use: External o modulation signal, 3.5mm headphone jack. Connect the o signal to the headphone jack, and turn the sliding potentiometer, you will hear the ringing sound and the LED lights up. The powersupply voltage is 5-12 V, using 2 lithium batteries powersupply, available external direct current powersupply. With LED working indicator light. Wide Applications: This emitter is used for debugging and maintaining the radio, radio station, SDR receiver, and other assemblies of the tool. Especially suitable for students to learn the working principle, practice production, and testing.  Specifications: Name: AM Emitter Circuit Board Material: printed circuit board Frequency ranges: 525-1605kHz Supplying voltage: 5-12V Item size: 87 * 87 * 42mm 3.43 * 3.43 * 1.65in Item weight: 114g 4.02ounce Package size: 133 * 131 * 53mm 5.24 * 5.16 * 2.09in Package weight: 170g 6.00ounce Packing List: 1 * AM Emitter Board