[Amps] Parasitics & Filament Sag

[Peter Chadwick]

Rich said:
> If an L-network was resonant on the operating frequency,  infinite  
current would flow through it because the reactive components are  
equal, opposite, in series, and not in parallel.<
Only because of your non-rigorous definition of resonance. AC theory tells us that the only definition of resonance that holds for all cases is that the applied voltage and current are in phase. The 'XL=XC' definition is a very loose approximation, and falls over badly when Q is low. There are occasions where it doesn't matter, but for an understanding of what is happening, it is necessary to appreciate the inherent errors in the approximation. The difference can be very important where feedback is applied, because a tuning error can lead to instability.
Ian says that in practice, it doesn't matter. Not to the  appliance operator, I suppose.
73
Peter G3RZP