This circuit is one of many that the reader can find in this section for testing crystals. The circuit uses an indicator LED. Transistor Q1 determines the maximum crystal frequency that can be tested.
We found this chopper circuit in a 1967 publication. The transistors are of the time, and current...
This circuit was found in a 1977 Radio Handbook. The ports used are CMOS like 4001 and the...
Ohmite TGHD non Inductive High Power Resistors Available in SOT-227 enclosures, these Ohmite...