This video by Ricardo Caratti demonstrates his method for controlling a Magnetic Loop antenna with an Arduino. The antenna’s tuning capacitor is adjusted using a stepper motor interfaced with the Arduino equipped to read IR commands sent from a compatible IR remote control. This allows the tuning capacitor to rotate clockwise and counterclockwise. Due to the high current demands of the stepper, he used a circuit based on the ULN2003 Darlington transistor array.
Regarding the antenna itself, he writes, “My Magnetic Loop antenna was based on models collected on the Internet. In particular, I used the instructions and tips from Alex (PY1AHD), which sells this kind of antenna with a better look than showed in this video.”