This circuit is from a 1969 General Electric manual. The SCR may be the TIC106. Similar circuits from other sources are found on this website.
We found this circuit in an American 1980s documentation. The transistors can be equivalent as BC548...
We found this circuit in an old publication on oscilloscopes. Its purpose is to observe the Ie /...
This circuit, called Kames Dandy, can mix signals from a wide range of frequencies and is...