The antenna power supply has been used mainly in vehicles manufactured by the Volkswagen Group (VW, Škoda, Audi, Seat) since 1998. Original car radios have a special phantom antenna power supply built in, but new aftermarket car radios do not. Therefore, if we want the amplifier in the antenna to work, we need to purchase a power supply that will solve the problem with the car antenna power supply. This is a so-called phantom power supply, i.e., via coaxial cable. There are several types of antenna power supplies, but the most commonly used are the basic ISO-DIN and FAKRA-DIN. The antenna power supply is connected between the new car radio and the antenna connector in the car. The antenna power supply always has a blue switching cable that connects to the switched positive on the opposite side of the ISO connector, usually position No. 5, blue or blue-white cable.