Why was the impedance for the broadband cable industry standardized at 75 ohms?

The standardization of impedance in the broadband cable industry at 75 ohms is primarily based on the need to balance several critical performance factors in the transmission of signals. The chosen impedance facilitates the delivery of high-frequency signals with minimal signal loss, which is vital for maintaining quality in data transmission over coaxial cables, particularly in television and broadband internet services.

Selecting 75 ohms allows for adequate breakdown voltage, meaning the cable can handle the electrical signals without risking damage or failure. This impedance also aids in minimizing attenuation, which is the loss of signal strength that can occur over distance. Attenuation is a crucial factor in cable design, as higher attenuation can lead to degraded signal quality. The 75-ohm standard is thus designed to optimize the trade-off between signal loss and performance, ensuring reliable communication over various lengths of cable.

This careful balance makes 75 ohms optimal given the intended applications in the broadband industry, where both signal integrity and efficiency are paramount for effective communication and data transfer.