Active Magnetic Loop Antenna HA SDR Short Wave Medium Wave Radio Loop Antenna Low Noise Adjustable Gain Antenna 100kHz-30MHz  The circuit board has reverse connection protection. The reverse connection of the power supply will not burn the chip, but the components cannot be soldered to the back of the circuit board, otherwise the chip will be burned.   There are battery buckles or terminals, 9 volt battery power can use battery buckles, other power supply can use terminals.  Note: The rear red wire port is positive (+) and the black wire port is negative (-). Please make sure the wiring is correct before powering on.  Shipping list:  1. Kits：  ① Main Board  ② Electronic components    2.Finished Board  ① Finished Board. ②Loop antenna x 1. (304 steel wire, steel wire Φ1.5mm, loop vibrator Φ50cm) Note: The battery is only for display, not included in the package Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Sold by-DIMEANI official store