This circuit is from an American 1967 documentation and can be implemented with modern equivalent transistors. The circuit serves as a Q multiplier.
We found this circuit with very high input resistance in an old documentation. The circuit is still...
August 2017 - Rectron's Schottky Barrier Diodes can now be obtained from Mouser Electronics. The...
This circuit with the known PLL 567 can be found in other versions in this section and in this...