In this receiver the is formed by 80 turns of wire 28 or close in a ferrite rod. The handset is low impedance and powered by a standard battery.
This high voltage power supply for gas laser tubes was found in the Radio Electronics magazine special...
This circuit uses a ceramic transducer to emit ultrasound whose frequency depends on C2. The...
We found this circuit in an old practical publication. The circuit is still viable today and the...