This circuit can generate signals in the VHF range and can be used as the basis for small transmitters. The frequency depends on the coil, which can have 2 to 8 turns for the range of 50 to 200 MHz.
The MC15555 of this circuit is the old version of the common 555. What this circuit does is...
We find this circuit in an American 1980s documentation. The circuit can still be assembled...
This circuit triggers an LM380 oscillator, producing an audio tone with light falling on the LDR....