Using a 4046 PLL, which is uncommon today, this circuit was found in the October 1994 issue of Electronics Now magazine. The circuit can be modified by changing the capacitor.
The cut-off frequency of the filter shown in the figure can be adjusted to values between...
This circuit was found in a Popular Electronics from the 90s. The components used are all common...
This circuit uses a dual floodgate MOSFET not very easy to obtain today. Its handling is very...