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.
This circuit was found in Electronics Now magazine and can be applied to any JFET. The circuit has high...
This circuit is from a 1977 National Semiconductor integrated circuits manual. The circuit admits...
This is a commercial radio circuit for 1967 AM. It was found in Japanese documentation. The...