This crystal tester was found on a 90s Ham Radio. Transistors are commonly used. The circuit is for testing crystals from 2 to 20 MHz.
This oscillator was found in the July 1993 Electronics Now magazine. The coil is wound with...
This circuit was obtained from an Electronics Design of 1964. The circuit makes use of tunnel...
This circuit was obtained in documentation on medical applications from 1966. The circuit is used in...