How is signal strength calculated in a coaxial cable system?

In a coaxial cable system, signal strength is an important measurement that takes into account several factors, including the original output power of the signal, the losses incurred due to the cable, and any additional losses from connectors. The correct formula provides a method to calculate the received signal level in dBmV by applying these factors appropriately.

When calculating the signal level, you start with the output power, which indicates the strength of the signal generated by the source. However, as the signal travels through the coaxial cable, it experiences attenuation or loss, which decreases its strength. This loss is reflected in the cable loss component of the formula. Additionally, each connector in the system may introduce its own loss, which is also subtracted from the output power.

Therefore, the correct calculation involves taking the output power and subtracting both cable loss and connector loss. This accurately represents the signal level as it reaches the end point of the coaxial cable system. This subtraction is crucial because it highlights that both types of loss contribute negatively to the signal strength.

Using this understanding, it becomes clear that the correct formula aligns with the physical principles of signal transmission and loss in coaxial cable systems.