This circuit was obtained from the March 1994 Electronics Now magazine. The circuit uses a common transistor which can be a low noise type such as the BC549.
Using the CMOS 4001 we found this circuit in the October 1974 Radio Electronics magazine. The...
One 4018 is used to divide the frequency of a digital signal by ten as shown here. The maximum...
This 90's project shows how to use an old cassette recorder to practice telegraphy. In position A of the...