# Antenna Inspection Antennas are finely-tuned instruments that can easily be damaged without noticing. Proper inspection of antennas at the time of installation during regular maintenance checks ensures your antennas operate the expected frequency and sensitivity. Both the antenna and coaxial cable are passive devices, meaning they do not require power to operate and instead are designed to carry radio energy from the environment to the receiver. ## About Antenna Tuning Antennas used in the Motus are tuned to listen to a narrow band of frequencies near the 'nominal' frequency (the frequency at which tags are manufactured to emit a signal). This helps reduce the amount of environmental noised being received. A poorly-tuned antenna will receive more noise and as a 'louder' signal than the real tag pulses they are built to detect. ## About coaxial cable Coaxial cables carry the signal from the antenna to the receiver with two conductors: central core and a coaxial shield, separated by an insulator. The coaxial shield protects the central core from interference. A damaged coax cable or connector can result in loss of the signal from the antenna and/or increased noise. ## Assessing Tuning Frequency using the NanoVNA {% embed url="" %} --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.motus.org/en/stations/station-inspection/antenna-inspection.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.