6 V x 5 mA regulator (CB21537E)

This 6V regulator with FET was found in an old Electronic Design. FET and transistor admit modern equivalents.

Two-state sequential (CB6566E)
Found in a 1970 documentation, this SCR bistable can be implemented with modern equivalent SCRs. Observe...
Tuning Indicator (CB16620E)
This circuit must have its input connected to the collector of the last IF transistor of the FM...
Increasing the voltage of a fixed regulator (CB8476E)
Found in a 90s Electronic Design, this suggestion to have a higher voltage in a fixed regulator...