We found this circuit in a 1965 magazine. The circuit can be assembled with current equivalent transistors and the precision in generating the frequencies depends on the tolerance of the capacitors.
Found in a 1964 Electronic Design, this circuit must use transistors according to the supplied...
This circuit powered by photovoltaic cells was found in the November 1998 issue of Electronics Now magazine....
This low impedance microphone preamp uses an operational amplifier with FET. The power supply must...