Dummy load

Small RF dummy load with capacity of 1 kW at frequencies up to 450 MHz. It consists of a 50Ω resistor immersed in oil to absorb the heat.
Large RF dummy load for shortwave transmitter at the Moosbrunn transmitting station of the Austrian Broadcasting Service, Moosbrunn, Austria. It uses a sodium hydroxide solution to absorb the radio energy, which is circulated through the radiator (center) to cool it. It has a capacity of 100 kW.

A dummy load is a device used to simulate an electrical load, usually for testing purposes. In radio a dummy antenna is connected to the output of a radio transmitter and electrically simulates an antenna, to allow the transmitter to be adjusted and tested without radiating radio waves. In audio systems, a dummy load is connected to the output of an amplifier to electrically simulate a loudspeaker, allowing the amplifier to be tested without producing sound. Load banks are connected to electrical power supplies to simulate the supply's intended electrical load for testing purposes.