One of the most important factors affecting the technical quality of a television picture is the amount of noise, or ‘snow’, on the picture. A television receiver produces noise if the signal from the antenna is weak, and the weaker the signal, the greater the amount of noise that is produced. Methods of predicting and measuring the signal strength are well established, but there appears to be no satisfactory reference in the literature describing what happens in the television receiver, and therefore this paper attempts to clarify and quantify the noise-related aspects of the performance of a television receiver. Following this, the study is extended to the antenna system, allowing us to show that the CCIR minimum field strengths are applicable in the context of modern receiving installations.