Found in a 90s 73 magazine for radio amateurs, this circuit makes use of common operational amplifiers.
This 6V regulator with FET was found in an old Electronic Design. FET and transistor admit modern...
Frequency Indicator (CB6342E) This simple circuit was found in an Exar publication from the 1970s....
The circuit shown in the figure differs from the previous one (CIR8909) in that it can be...