Using the CMOS IC 4046 we found this VCO in the November 1984 Radio Electronics magazine. The center frequency is given by the capacitor. The maximum frequency is around a few megahertz.
This circuit was obtained in a 1975 documentation. It is intended for old vehicles that still use...
This circuit uses a diode as a radiation sensor. The operational ones are old because the...
This circuit was found in the March 1999 issue of Electronics Now magazine. The meter is analog and...