The values of the indicated components in this circuit of a 1967 Electronics World, are for a frequency of 512 kHz. The power can be between 6 and 22 V and the FET is a general-purpose type.
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....