This circuit was obtained from Popular Electronics of the 1990s. The circuit uses common transistors today and the frequency is given by the crystal.
Indicated for scanning circuit applications, we found this generator in a Radio Electronics from the 80s....
This circuit tests crystals up to a few megahertz with ease. The circuit is from a 1977...
Found in documentation from the 70s, this circuit uses an operational one from that time. It goes for...