Found in 1980s Electronics Design, this circuit covers 4 decades of frequencies with a unique control. A multi-turn trimpot is used for fine adjustment. The frequency range depends on C1.
We found this circuit for old tape recorders in the December 1972 Radio Electronics magazine. The...
I found this simple circuit from an English magazine from 1984. The circuit can be easily...
This windshield wiper interval was found in an old documentation. The SCR can be the C106 and the...