How to model and understand the asymmetry of a parallel RLC circuit spectrum
The RCL circuit is actually a shielded inductor, so a solenoid inside
  of a copper can essentially. The capacitance is parasitic coming from
  coil-to-coil and coil-to-shield interactions.


This means that the noise comes from the inductor's series resistance and therefore is not parallel to the inductor but in series: -







simulate this circuit &ndash; Schematic created using CircuitLab

For the above (and below) I've made an estimate of the R, L and C values to roughly match the peak in the response at 29.6 MHz.

If so, then the 2nd order filter characteristic is low pass and not band pass such as shown with this on-line simulator: -



The red trace above is the response of a low pass 2nd-order filter and not a band-pass filter - might it look familiar?