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 1970 publication by General Electric. The components can be changed...
This source is used to supply circuits with operational amplifiers, being originally created for...
Suggested by American documentation from 1968, this circuit divides the frequency of synchronized...