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This example resonates at 230MHz!, but can easily go higher! You can alter the resonant frequency in 3 different ways actually:
1. The values of the inductors and Capacitor; although, unfortunately, it’s a little more complicated than just calculating 2-component LC resonance
***Edited: originally I mentioned the frequency could be calculated from simple LC resonance formula, but it seems this circuit has a few complex impedances and phase shifts, not to mention the more obvious extra inductor… all of which make it a bit hard to predict the actual frequency of oscillation, but it seems it can be approximated by ensuring you pick each reactive component so that it has a Reactance (X) of 100 Ohms at resonance; This has worked best for me, but might vary a lot depending on the transistors used, and especially the resistor, just keep the resistor at 1k ohm to keep things simple. Nevertheless, it does work fairly well for higher frequencies if that’s what you need***
Keeping the Inductors/Capacitor constant, the other influential factors are:
2. The size of the resistor; being inversely proportional to the resonant frequency
3. The current; being directly proportional to frequency.
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