This circuit was found on an 80's Ham Radio. The transistor admits equivalent. The circuit can generate 20 to 100 MHz signals operating at the fifth harmonic of the crystal.
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....