A Comparison of Detectors

Author: J.B. Hoag

In judging the performance of a detector, we are concerned with the following factors: (1) the sensitivity or ratio of a.f. output to r.f. input; (2) the linearity or accuracy of reproduction of the wave form of the modulation on the incoming signal; (3) the loading effect of the detector on the tuned circuit in the input. Heavy loading lowers the Q of this circuit, broadens its resonance curve, and makes it less selective; (4) the input ability of the detector to handle large amplitude input signals without overloading. A comparison of the various types of detectors just discussed is given in the accompanying table.

Detector Type	Sensitivity	Linearity	Selectivity	Input Ability
Diode	Low	Good	Poor	High
Plate	Medium	Good	Excellent	Medium
Grid Leak	High	Poor	Poor	Limited
Regenerative	Higher	Poor	Excellent	Poor
Super-Regenerative	Still higher	Good	Poor	Medium