We found this circuit in the June 1984 issue of Radio Electronics magazine. The circuit uses an integrated circuit that is not very common today.
The circuit shown in the figure has elements for maximum gain at maximum speed. By setting the...
This instrument, based on a 555, measures frequencies up to 1 kHz, but its scale can be modified by...
Using a CA3130 operational amplifier, this circuit was found in an English publication from 1977....