This automotive circuit was obtained from an 80's schematic from the integrated circuit factory itself. The voltage regulator is still common, but the operational amplifier is of the time.
This antenna for the frequencies 146 or 440 MHz was found in a magazine 73 for Amateur Radio of...
We found this circuit in an 80's EDN. The circuit makes use of a MAX680, being given a table with...
This circuit was found in a 1986 publication. However, it can still be easily assembled, as the...