What is the most common impedance of coaxial cables used in amateur radio?
8 ohms
8 ohms is incorrect because it is far too low for standard coaxial cables used in RF applications, which require higher impedance to ensure efficient signal transmission.
50 ohms
50 ohms is correct, as it is the industry standard impedance for most coaxial cables used in amateur radio, balancing efficient power transfer and minimal signal loss.
600 ohms
600 ohms is incorrect because it is an impedance value typically associated with telephone and audio applications rather than RF communications, where it would cause significant mismatch and signal loss.
12 ohms
12 ohms is incorrect because it is not a standard impedance for coaxial cables in any RF applications and would lead to inefficient signal transmission.
Explanation
Impedance is an essential concept in amateur radio, particularly when dealing with transmission lines such as coaxial cables. The impedance of a cable impacts how effectively it can transfer radio frequency (RF) signals between equipment, such as a transmitter and an antenna. In amateur radio, the most commonly used impedance for coaxial cables is 50 ohms. This standard arose because a 50-ohm impedance provides a good balance between power handling capability and low signal loss, making it ideal for use in a wide range of hobbyist and professional applications.
T9B02 2022-2026