The L1 coil is formed by 4 turns of wire 20 in the form of 0.5 to 0.6 cm without core. The circuit is from an 80's documentation. The range reaches a few tens of meters.
This traditional oscillator uses two complementary transistors to produce low frequency signals....
This oscillator produces a rectangular signal in the range of 100 Hz to 1k Hz but with the change of...
This electronic “windsock” is operated by a magnetic switching system. It was found in a Radio...