Re: Resonator base impedance (help needed)

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Original poster: "Antonio Carlos M. de Queiroz by way of Terry Fritz <twftesla-at-uswest-dot-net>" <acmq-at-compuland-dot-com.br>

Tesla list wrote:
> 
> Original poster: "R.E.Burnett by way of Terry Fritz
<twftesla-at-uswest-dot-net>" <R.E.Burnett-at-newcastle.ac.uk>

> Also,  since a resonator can be modelled as a series RLC circuit in
> which Xl and Xc cancel out at resonance,  then the input impedance
> would seem to be a pure resistance equal to R ???  Does this mean
> that the usual measures taken to increase Q factor (minimise R) will
> also decrease the base impedance of a given resonator ???
> 
> I have only seen mention of base impedance in Gary Johnsons paper.
> This refers to DC resistance,  skin effect,  radiation resistance,
> etc..  but does not give an explanation for the measured Zbase.

If you model the secondary+terminal as a series RLC circuit (what
works very well), the input impedance at the base at resonance is
really just a resistor. It's the coil resistance at the resonance
frequency, That depends on the DC resistance of the wire, the skin
effect increasing this resistance (maybe several times), the radiation
resistance of the coil, seen as an antenna (takes into account the
radiated energy), and also losses in the dielectrics (coil form),
induced currents in nearby objects, etc. 
Yes, if you increase the Q of the system the resistance drops.

Antonio Carlos M. de Queiroz