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 is a common crystal oscillator configuration with 80s transistors. The circuit has the...
This circuit was found in a 90’s RF design. The circuit has an output frequency of approximately 100...
This one-digit photometer using CMOS circuits was found in a 1989 documentation. The circuit is...