Found on an 80's Elektor, this circuit uses common components, being the diode a general purpose germanium. The coils select the frequency range of the indicator that reaches 60 MHz.
This speed control for motors up to 500 mA was obtained in an old European documentation, but it...
This circuit cuts a rectangular signal, and a trapezoidal signal is obtained. The circuit is from...
This low frequency sinusoidal oscillator was obtained in documentation from the 1970s. Operational...