This filter was found in an 80's English publication. However, it can be implemented with modern operating systems. The circuit can tune frequencies in a range from 10,000 to 1.
This circuit was discovered in an English publication in 1979. The circuit can still be assembled with...
This circuit is the digital indicator for the previous circuit and can be used with similar...
This circuit tests crystals up to a few megahertz with ease. The circuit is from a 1977...