 a dummy load is a device used to simulate an electrical load, usually for testing purposes. ==radio==  in radio this device is also known as a dummy antenna or a radio frequency termination. it is a device used in place of an antenna to aid in testing a radio transmitter. it is substituted for the antenna while adjusting the transmitter, so that the transmitter does not interfere with other radio transmitters during the adjustments.  if a transmitter is tested without a load, such as an antenna or a dummy load, the transmitter can be damaged. also, if a transmitter is adjusted without a load, it will operate differently as compared with a load, and the adjustments may be incorrect. the dummy load ordinarily should be a pure resistance; the amount of resistance should be the same as the impedance of the antenna or transmission line that is used with the transmitter (usually 50 Î© or 75 Î©). the radio energy that is absorbed by the dummy load is converted to heat. a dummy load must be chosen or designed to tolerate the amount of power that can be delivered by the transmitter.  the ideal dummy load provides a standing wave ratio (swr) of 1:1 at the given impedance. veterinarian-grade mineral oil, an inexpensive source for mineral oil, is frequently used by amateur radio operators as coolant in rf dummy loads. ==audio== thumb|upright|four heavy duty dummy loads used at an amplifier shootout when testing audio amplifiers, it is common to replace the loudspeaker with a dummy load, so that the amplifier's handling of large power levels can be tested without actually producing intense sound. the simplest is a resistor bank to simulate the voice coil's resistance. for loudspeaker simulation, a more complex network is more accurate, however, as actual loudspeakers are reactive and non-linear. there are many designs for loudspeaker simulators, which emphasize different characteristics of the actual speaker, such as the voice coil's inductance, mechanical suspension complianc
Radio_electronics