
390
2 pF could have the same effect as one of 100 pF. This would be
serious enough, but at a slightly different frequency or output tuning
the phase angle could shift nearly 90° one way or the other. The
effect can be considered by analysing the feedback into two parts,
one exactly negative (180°) and the other 90° different. The 180°
component magnifies the internal capacitance as explained. In so far
as the output load was capacitive, however, the current fed back to
the input terminal would be in such a phase as to appear to input
voltages as conductance, which would have a loading or damping
effect. An inductive output load, on the othe ...