Found in American documentation from the 1990s, this circuit generates signals in the 350 to 500 MHz range. The output power is in the order of 100 mW at 50 ohms.
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....