Flexible test cable

A flexible test cable has a center conductor (210), a conductive sleeve (240) with an effective electrical length equal to an odd quarter wavelength of a frequency of interest, a dielectric spacer (230) located inside the conductive sleeve (240) for preventing a portion of the center conductor from electrically coupling to the conductive sleeve, and a dielectric joint (220) for maintaining a portion of the center conductor in the middle of an end of the conductive sleeve (240). The conductive sleeve (240) can have a variety of cross-sectional shapes. The dielectric spacer (230) can be formed in a variety of shapes from rigid or compressible dielectric materials. Likewise, the dielectric joint (220) can be formed in a variety of shapes from rigid or compressible dielectric materials. Using the dielectric joint (220) to link together multiple conductive sleeves (240) results in a flexible test cable (200) with electrical transparency at the frequency of interest.