VLF Receivers for SIDs This page has information about building VLF Receivers to detect SIDs & Natural VLF Emissions Two types of receivers are reviewed in some detail, with other types mentioned. 1 VLF Loop Antenna Receivers 2 Mu Metal & Ferrite Cored Antenna Receivers VLF Loop Antenna Receivers A simple loop antenna is cheap and easy to construct and can be easily connected to a high gain audio amplifier as a receiver. A block diagram of a typical system is shown below. The antenna can be constructed in many ways. One example is shown below where a 1m by 1m loop is wound around wooden pegs supported on a wooden cross frame. The loop can be wound from any wire, but reasonably thick copper wire (about 1mm diameter) will give good results as the coil resistance will be low. The wire should be insulated with plastic covering, or enameled wire can be used. In the example shown below 40 turns of wire are employed. The number of turns, the diameter of the wire and the area of...