Below is a button URL link to one of my google site blogs. This particular blog site relates to a few ideas I have had regarding radio design. The ideas may be off hand, but I have discovered a few items that although have been regarded as holly in some eyes, I have found are not quite the case as it seems.
One particular discovery that came to hand while circuit testing a purchased “AV amplifier”, the decoupling emitter capacitance of a common emitter transistor amplifier unfortunately shifts the designed d.c. bias point of the transistor circuit. The noticeable distortion effect is depended upon the capacitance reactance across the emitter resistor, but never the less, without the emitter circuit decoupling capacitor for the so called A.C. circuit gain figures, the signal reproduction was excellent all across the circuit performance design. The A.C. signal I found just cycles up and down from the d.c. bias point of the circuit amplifier.
I have wondered if a similar effect would occur at an R.F. Level, any where within the radio circuits, not just on the transmitter amplifier stage. It is however food for thought regarding to signal distortion and the varies definitions of signal harmonic parameters.