Using the LM383 this circuit was found in a Popular Electronics from the 90s. The source must be 14V and the integrated circuits must have good heat sinks.
This conventional series reducer circuit reduces the voltage of a 12 V battery to the selected value...
In the figure we have a converter that generates a negative voltage from a positive voltage...
This circuit covers the bands from 1.8 to 150 MHz, with plug-in coils whose characteristics are...