Shortwave AM Transmitter Board Power supply: DC 9V 2A current 50-80MA Frequency: 21MHZ crystal frequency stabilization Adjustment amplitude: 45% High frequency power: 100 mW Modulation method: transformer high potential modulation Audio source: external audio source. Mobile phone available. MP3 PC, etc. Launch distance: about 10M Difficulty of parts: Welding. No debugging required Suitable for: Radio hobby. Student lab test Specification: A-DIY KITS unassembled Color: As Shown Material: PC+metal Package Contents: 1 x Shortwave AM radio transmitter board Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.