If you increase the resistance in a RLC series curcuit will it give you broader tuning at the resonant frequency?

 

If you increase the resistance in a RLC series curcuit will it give you broader tuning at the resonant frequency?

Yep. And lower Q

 

But that should increase impedance, shouldn't it? Which you don't want to have too high of a impedance.

 

But that should increase impedance, shouldn't it? Which you don't want to have too high of a impedance.

At precise resonance, the ONLY impedance you'll see is the resistance.

Depending on the application, you don't always have a choice of the resistance. An antenna is a perfect example. An antenna is electrically equivalent to a series resonant circuit. The radiation resistance is pretty well determined by the physical size of the antenna. And actually, for an antenna, it's GOOD to have a high radiation resistance, which generally lowers the Q of the circuit.

In any case, the Q is determined by X/R, so all other things being equal, a larger L/C ratio wil result in a narrower bandwidth (for a simple series circuit).

Eric