This circuit is from a 2004 documentation serving for signals from 1 MHz to 160 MHz. The antenna is of the telescopic type and the analog instrument is of the type found in old sound equipment.
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....