A portable electronic device for detecting an electromagnetic pulse generated by a tesla coil, and selectively a pulse from natural lightning. The device has a detection circuit for electromagnetic pulses, operating to detect an observed electromagnetic pulse having a frequency at least within a range of about 50 kilohertz (kHz) to about 300 megahertz (MHz). The detection circuit generate an output signal corresponding to the observed electromagnetic pulse. A microcontroller analyzes the output signal from the detection circuit against a tesla profile that identifies a detected electromagnetic pulse as a tesla coil pulse when the observed electromagnetic pulse has a frequency within the range of about 50 kHz to about 300 MHz with a pulse duration of at least 0.50 seconds. The microcontroller then generates an indication that the detected electromagnetic pulse is that of a tesla coil, and generates a tesla coil alert, typically flashing of an LED.