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Interconnects, speaker wire, power cords. Ask the Cable Guys.

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Characteristic Impedance

Posted by Duster on March 20, 2012 at 21:39:41:
A 75 ohm cable can be either solid core or stranded. A specific diameter is based on the characteristic impedance of a particular cable design. As such, there can be large diameter coaxial cables, and small diameter mini-coaxial cables, both with 75 ohm characteristic impedance.

Taken from Wikipedia - Coaxial cable:

"The characteristic impedance of the cable is determined by the dielectric constant of the inner insulator and the radii of the inner and outer conductors. A controlled cable characteristic impedance is important because the source and load impedance should be matched to ensure maximum power transfer and minimum Standing Wave Ratio. Other important properties of coaxial cable include attenuation as a function of frequency, voltage handling capability, and shield quality."

So, the relationship of the center conductor, the dielectric (insulator), and the outer shield/return conductor is what determines what a 75 ohm characteristic cable is, not the kind of wire that's being used as a center conductor.

See link: