Cross-over point detector

Usually, the -3 dB (and -20 dB) roll-off points on the frequency characteristic of a filter are found with the aid of an oscilloscope or a milli voltmeter. Not everyone has these instruments available, however, and it is primarily for these designers that the detector described in this article is intended . Nevertheless, even if you already have a suitable oscilloscope, you will find the detector a handy addition to your workshop instruments.