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 is from the time when photos were revealed in darkrooms. We found it in a 1968...
This is a commercial circuit that can be found in several publications from the 80s and 90s and...
April 2017 - Mouser Electronics already has in stock the new HMC8400, Analog Devices low noise...