Found in a 1980s American documentation, this circuit is intended for amplifying 10.7 MHz video signals, with a gain of 100dB.
This circuit is a from publication 1980, but still can be mounted with BC548 transistors for Q1...
This circuit for testing zener diodes by lifting their curve on an oscilloscope was presented in...
This high quality circuit with complementary symmetry was found in an Electronics World of 1966....