Define and differentiate between coax loss and total feedline loss in RF systems.

• A. They are the same
• B. Coax loss is attenuation in the coax with frequency; feedline loss includes connectors and adapters in addition to coax.
• C. Coax loss is DC, feedline is AC
• D. Coax loss depends on weather, feedline does not

Answer: (B)

Coax loss is the attenuation that happens inside the coax itself as the RF signal travels, caused by the conductor resistance, dielectric losses, and skin-effect losses in the cable. This loss increases with frequency and with length, and it’s often given as a dB per unit length at a specific frequency so you can calculate it for any run.

Total feedline loss, on the other hand, is everything that reduces signal power along the entire path from source to load. That means you take the coax loss and add the losses from all other components in the path—connectors, adapters, tees, attenuators, terminations, and any other fittings. Each connector or adapter contributes a small fixed loss, and those are summed with the coax loss to get the total.

So, you can think of coax loss as the intrinsic attenuation of the cable itself, while total feedline loss is the full attenuation experienced as the signal passes through coax plus all the ancillary components.