We found this circuit in a Radio Electronics from October 1963. The circuit uses an output transformer with a center tap. The trimpot is adjusted for higher gain and lower quiescent current.
This was one of the National Semiconductor clock modules very popular in the 70s and 80s. In the...
This circuit is from 2001 documentation, serving to multiplex stereo signals for FM transmitters. The...
EDN magazine in a 90's issue published this TTL technology debouncer flip flop circuit, in this...