Patent ID: 7863886

Claim:
A method for determining the resonant frequencies of a power transmission line carrier line trap of the type whose blocking characteristics are a function of its resonant frequencies comprising: a) injecting a signal into the transmission line over a range of frequencies, where the range of frequencies includes at least one of the line trap's expected resonant frequencies; b) measuring the magnetic field strength produced by the current through the line trap's main coil; c) measuring the magnetic field strength produced by the total current flowing through the line trap; d) computing the ratio of the strength of the magnetic field produced by electric current flowing through the line trap's main coil to the strength of the magnetic field produced by electric current through the entire line trap, where said ratio is computed over a range of frequencies that includes the expected resonant frequency(s) of the line trap, such that the resonant frequencies are indicated where said ratio is at a local maxima or minima.