Why did the cable industry choose 75-ohm coaxial cable — and not 50 ohms? The answer is rooted in physics, engineering tradeoffs, and decisions made decades ago that still define every HFC network running DOCSIS today. Brady Volpe and Ron Hranac break down one of the most fundamental design choices in cable network history: why 75-ohm characteristic impedance became the standard for outside plant, Why did the cable industry choose 75-ohm coaxial cable — and not 50 ohms? The answer is rooted in physics, engineering tradeoffs, and decisions