This circuit was found in a Signetics documentation from the 1980s. The integrated is a PLL and the SCR is a general purpose type The pitch frequency is given by R1 and C1 as formula next to the diagram.
We found this circuit in a 1988 documentation, but the components used are still current. The...
In the figure we show a monostable that uses two of the four ports available on 4001. The duration of...
If interference occurs in several receivers, much more interesting than placing a filter on each...