File:Tesla-Magnifier-Electrostatic.svg

English: In a classic Tesla coil the primary drives the ground end of the secondary coil to form the driver transformer, which resonates the entire secondary coil. In the magnifying transmitter the driving and resonating parts of the secondary are separate coils. From a circuit analysis standpoint, there is little difference between the classic coil and the magnifier.

The extra coil or helical resonator can be physically separated from the two close-coupled coils which comprise the master oscillator or driver section. The power from the master oscillator is fed to the lower end of the extra coil resonator through a large diameter electrical conductor or pipe to minimize corona. The magnifying transmitter's base-driven extra coil behaves as a slow-wave helical resonator, the axial disturbance propagating at a velocity of less than 1% up to around 10% the speed of light in free space. The Magnifying Transmitter's axial velocity electromagnetic field is established by the coil pitch and electrical charge propagation speed through the circuit. It is interesting to note that rigorous mathematical descriptions of Tesla's Magnifier did not become available until 50-100 years after Tesla's pioneering work. Modern analyses have succeeded in applying distributed "transmission line" descriptions of the "extra coil" rather than the usual lumped-constant analysis. Upon validation, recently developed models of resonator behavior show that distributed analysis is more accurate for all excitation modes. Nevertheless, lumped analysis can be used to design Tesla coils and magnifiers.