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 is intended to match impedances for observing signals on an oscilloscope. The FET...
The battery is charged by the photocell that keeps the low consumption beacon in the dark. The...
This is the configuration suggested by National Semiconductor for cascading the LM12. The LM12...