This circuit was found in an 80's Electronic Design. It amplifies TTL fast signals for a coaxial cable. TTL is from the S (Schottky) line and transistors are types of the time.
This circuit was found in Motorola documentation from 1966. The lamps are according to power and...
This circuit, which uses components still common today, was found in a 1997 documentation. It...
This circuit is intended to apply the music signal from a stereo to a telephone line for the...