Old electronic instruments and audio amplifiers often use electronic tubes for rectification to obtain high voltage DC
Point contact diodes are only suitable for low current rectification due to their small contact points,
Crystal diodes can generally be used for over 100000 hours.
To determine the quality of a diode, the following methods can be used:
Polar tubes should be considered as the elders of the semiconductor device family
By utilizing the unidirectional conductivity of diodes
