Which of the following can cause signal interference in a coaxial system?

Poor connections in a coaxial system can lead to signal interference because they can create an inconsistent pathway for the signal to travel. If the connections between cables, connectors, or devices are not secure or well-made, it can result in signal degradation, increased losses, and potential noise being introduced into the signal. This kind of physical imperfection can obstruct the signal clearly from reaching the intended destination, causing various issues such as fuzziness in video signals or interruptions in data transmission.

While high voltage power lines can certainly cause interference, their effect is more related to electromagnetic interference rather than a direct issue within the coaxial system itself. Physical obstructions and weather conditions can impact signal quality as well, but they are not the primary causes of interference within the coaxial system as directly as poor connections are. Properly maintaining connections is vital for ensuring the integrity and quality of transmissions within coaxial cables.