We found this circuit for musical instruments in the March 1992 Radio Electronics magazine. The circuit has outputs according to the desired scale from a crystal oscillator at the indicated frequency.
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...