These circuits were found in the February 1995 issue of Electronics Now magazine. The circuits have normal response in (a), boost in (b), cut in (c), and plate response in (d).
We found this circuit in the 1983 Radio Electronics Special projects magazine. The components are...
With the presented circuit it is possible to detect signals from transmitters in a frequency range...
This circuit was found in a British documentation from 1969. It can be implemented with modern...