Found in an English publication from the 1980s, this circuit can be built with equivalent transistors such as the BC549. The signal must be applied to an external amplifier.
This circuit was found in the September 1984 issue of Radio Electronics magazine. The frequency is given...
We found this circuit in an Argentine documentation from 1973. The transistor admits a more modern...
This triac synchronized circuit was found in the July 1995 issue of Electronics Now magazine. The...