We found this circuit in the Electronics Experimenter Handbook magazine from 1993. L1 has 2 = 2 turns of 28 or 30 wire in the shape of 0.5 cm without core. The range reaches a few tens of meters.
This circuit was obtained from HAM Radio magazine in an 80's issue. The FETs are types of the time...
Found in the September 1992 issue of Radio Electronics magazine. This circuit generates pulses that...
This blocking oscillator circuit was found in a Radio Electronics from November 1963. The...