Found in a 90’s Popular Electronics, this circuit generates sinusoidal signals with frequency controlled by an input signal. C4, C3 and C1 together with R12 and R3 determine the frequency generated.
Published in an old Popular Electronics, this circuit makes use of components that are still...
Suggested for the control of photographic enlargers, this 1967 General Electric circuit uses still...
Found in old documentation, this oscillator operates with high voltage. The diode must be of the...