This circuit was suggested by Motorola in a 1980s publication. It is based on a PUT that is not a common component today. The division depends on the capacitor values according to the table.
We found this Vox in a 1969 Motorola documentation. Transistors support modern equivalents and the SCR can...
Suggested by Texas Instruments in 1968 documentation, this circuit uses components from the era....
This very low frequency circuit was found in a 1964 Electronic Design. Transistors may be modern...