More specifically, I have an NMOS oscillator, where the output is taken from the source terminal. I have to couple the output (50 Ohm load) with a coupling capacitor, but is this going to affect my calculations of the resonant frequency of the circuit? In my case, I have a Clapp oscillator (Capacitive feedback divider). When the load is connected, however, the Coupling cap + R_load appear, in effect, in parallel with my feedback capacitor. How should I implement this in my calculations?