Based on a unijunction transistor, this circuit was found in the January 1994 issue of Electronics Now magazine. The frequency range depends on C1, which can be changed.
This basic buffer circuit can be implemented with other operational amplifiers. The circuit is...
Found in old American documentation, this circuit can use crystals between 27.5 and 33 MHz...
This circuit was suggested by Siliconix in a 1980s publication. The circuit uses components from the time...