This circuit was found in documentation from the 1970s. However, it can be implemented with modern transistors such as 2N2222 for Q1 and BF494 for Q2. The crystal depends on the desired frequency.
This circuit was found in a Popular Electronics from the 90's. It consists of the solid-state...
Radio Electronics published this circuit in a 90's edition. The circuit makes use of an uncommon...
Other operational amplifiers from the same family such as MC34002, MC35001, MC34004 and MC35004 can...