In Practice

摘要

How much sensitivity can you really 'use' on the VHF and UHF bands, before you are limited by external noise? This is a complex topic, but you have already understood the main point: when a receiver is connected to an antenna, the signal-to-noise ratio is limited by the amount of external noise that accompanies the incoming signal. With a very low-noise receiver you can approach that fundamental limit, but there are other penalties involved as we shall see.