What is the effect of feedline loss on system performance?

• A. Increases the transmitted power and improves overall efficiency.
• B. Reduces delivered power, degrades VSWR and SNR; must be minimized with proper impedance and platform.
• C. Has no impact on system performance.
• D. Only affects receive-side performance.

Answer: (D)

Feedline loss is the power lost as heat in the coax and connectors as the RF signal travels. This attenuation affects both transmitting and receiving. On transmit, less power actually reaches the antenna, so the radiated power and overall efficiency drop. On receive, the signal coming from the antenna is weakened as it passes through the line, reducing the signal level at the receiver input and lowering the SNR. This loss is not the same thing as VSWR, which is about impedance mismatch and reflections; improving matching helps reduce SWR, but it doesn’t remove line attenuation. To minimize the impact, use a low-loss feedline appropriate for the frequency, keep runs as short as practical, and use quality connectors and proper installation.