ARRL Technician Practice Exam

What aspect of coaxial cable design helps to minimize loss?

1. The thickness of the outer jacket

2. The materials used in the dielectric

3. The length of the cable

4. The color of the cable

The correct answer is: The materials used in the dielectric

The design of coaxial cables incorporates specific materials in the dielectric layer to minimize signal loss. The dielectric is the insulating material that separates the inner conductor from the outer conductor in coaxial cable. Selecting high-quality materials with low loss characteristics, such as foam polyethylene or other specialized plastics, plays a crucial role in maintaining the integrity of the signal as it travels through the cable. When the dielectric has a low dissipation factor, it reduces the amount of signal energy that is converted to heat, thereby preserving more of the original signal strength over distance. This is particularly important for long runs of coaxial cable, where losses can accumulate significantly. While the thickness of the outer jacket, the length of the cable, and the cable color can affect some physical characteristics and durability, they do not contribute as directly to minimizing signal loss as the materials used in the dielectric do.