Tank circuit series resonant

The peak current value of the fundamental frequency component in the load, /ad is the coefficient of the fundamental frequency component of the Fourier series of the collector current All harmonic current is shunted to ground by the tank circuit capacitor and assumed to be zero. The tank circuit is resonant at the fundamental frequency. 

Fig. 2.5.3 Typical NMR resonant tank circuit, showing coil loss mechanisms. This LC circuit is then placed in series with two matching capacitors (Cmatch). The resistance of the circuit is represented by Rco], the inductive losses by Rm and the dielectric losses by Ci, Cd and Rd.

Once the coil has been incorporated into a tank circuit, a dip meter can be used to measure the resonance frequency. For a parallel resonant circuit, the dip meter can be used in the usual way, i.e., look for a "dip" indication as a function of frequency. For a series tank circuit, it is best to use the dip meter as an rf source acting like an artificial NMR signal and maximize the receiver output when the receiving system is fully hooked up. This will work also for the parallel tank. (See section V.C.9. on impedance matching.)... 

A coil in a series tank circuit has the advantage that it is easy to rig in a remote location (as in a dewar tail). Unlike the parallel resonance circuit discussed above, the series tank circuit presents a low impedance to the outside world, i.e., much current with little voltage. [This low impedance could also be an advantage over the high impedance of the parallel tank in dissipating the rf energy after the transmitter shuts off. There are other ways to improve the receiver recovery (see V.A.4.), however, so this in itself is not sufficient reason to choose a series tank circuit.]... 

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