This circuit provides both frequency and voltage division. The circuit was found in a 1966 documentation. The circuit must be supplied with voltages from 32 to 40 V.
The transistors are 2N918, 2N3464 and other RF equivalents of the time for Q1. For Q2, 2N3399, 2N2894...
This circuit, which can be used as a shield, was found in a 90s Electronic Design. The circuit...
This interesting intercom circuit was obtained from an Argentine publication from the 1970s....