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 circuit was obtained from a Radio Electronics from the 90's. It can generate signals up to a...
For cars that had the positive pole of the battery in the chassis, Radio Electronics magazine from...
Found in American documentation from the 1980s, this circuit uses an ADC from that time, which is...