dalarev said:
What's the matter...wrong forum?
/bump
OK, I´ll try to give you some hints.
In general, you have two alternatives to analyze the CLAPP oscillator:
a) The circuit is considered as a two pole oscillator based on the negative resistance principle. In this case, there is no "Barkhausen" criterion because this condition is based on the principle mentioned in b). The oscillation condition requires that at a certain frequency a grounded positive resistance is in parallel with a negative resistance with a value which is equal or somewhat larger.
b) For my opinion, it is easier to see the CLAPP oscillator as a four-pole circuit which has to fulfill the Barkhausen criterion (loop gain equal or a bit larger than unity).
For this purpose, you have to redraw the circuit with the aim to see an active part (transistor) and a feedback circuitry.
Advice: Apply the principle of virtual ground, which in fact is nothing else than to select another reference point. To do this, you 1.) connect the source pin to ground (now you have a common source stage) and 2.) you disconnect all grounded elements from ground potential but leave them connected with each other. Now you have an amplifier and a frequency selective feedback network which can be analyzed as usual (by hand calculation or by simulation).
Further questions?
Good luck
LvW
Added after 3 hours 8 minutes:
In addition to my comments, here is a link for a corresponding article:
**broken link removed**