Gain 10 amplifier with the L161 (CB9012E)

The L161 is an operational amplifier from the 70s, uncommon today. The indicated circuit has a product gain x pass band of 100 kHz.

UAA180 VU-Meter (CB12348E)
The UAA180 integrated circuit is no longer manufactured, but if the reader finds one in a scrap...
Voltage to frequency converter with potentiometer (CB6995E)
This application circuit for the AD6521C was found in Radio Electronics from the 90's. The circuit...
Water level meter (CB6959E)
This interesting capacitive water level sensor was found in Popular Electronics. The circuit can be...