Transistor gain meter (CB20522E)

This circuit was found in a publication in the 1950s, mainly applying to germanium transistors of the time.

SCA3300 D01 3 Axis Accelerometer and Inclinometer
May 2017 - Mouser Electronics announces the availability of the new Murata SCA3300-D01 3-axis...
Precision light level detector (CB20699E)
In this circuit R1 has 2M5, R2 and R3 are 5M obtaining a detection current for the diode of 0.5...
Regenerative WWV receiver (CB20272E)
WWV is the American broadcaster of hourly signals and frequency standards that operates at 3.5...