Performance requirements for television transmission are discussed in relation to reliability. Modulating systems are reviewed, and it is concluded that high-level modulating systems are to be preferred where the choice of system exists.The design features of a current 50-kW transmitter are discussed with special reference to shunt-regulated amplifiers, pulse stabilization methods and black-level control. Overall performance figures are quoted.Transmitter testing requirements are discussed, and a case is made for a controlled shape of step signal for transient testing and for the use of very-low-frequency testing for overall system appraisal.