This circuit with 24 dB per octave attenuation was found in the November 1973 Radio Electronics magazine. The components are for 1 kHz but can be recalculated for other frequencies.
The figure shows how to generate a 60 Hz clock signal for TTL circuits. The circuit is from Radio...
This circuit for an isolated instrument or multimeter can increase the sensitivity of your...
Although it is a common configuration today, this circuit was taken from an old publication. The...