Re: Colpitts oscillator
If the goal is only to make a Colpitts oscillator, don't waste time to simulatie, try it in the lab. The only thing you have to take care is that if fmax is large enough or not.
Besides that, you can(for real application, this is a MUST) add a buffer as a output driver to isolate the LC tank. And a high impedance high frequency probe helps a lot, because spetrum cause a 50ohm load unless you transform this impedance to a high impedance.