Hz to 10 KHz. You will hear world-wide lightning static, tweeks, whistlers, auroral noise, etc. For extreme sensitivity and room-filling volume, connect the audio output of this receiver directly to the microphone input jack or L.L. jack of your audio amplifier or tape recorder. This will help reduce humming noise . Use more than 10 feet of wire in your antenna.
Longer antennas give louder volume and more sensitivity.
Rotating the antenna will reduce or eliminate power line hum. You will have to experiment with the antenna to get hum-free reception. You can take this portable receiver with you to locations away from power lines to hear VLF radio waves without the power-line hum that is so common in residential areas. The sound you hear is the wire vibrating in the Earth's magnetic field. Use this receiver to experimentally investigate interupted DC current flows from the thundercloud to earth through the tornado.