This circuit was found in documentation from 1844. It consists of an economical solution for times of war. The coil determines the frequency range and the power comes from the power grid itself. Listening is through high impedance headphones.

This circuit was found in documentation from 1844. It consists of an economical solution for times of war. The coil determines the frequency range and the power comes from the power grid itself. Listening is through high impedance headphones.