A) To prevent the radiation of signals when making tests
A "dummy load" is essentially a large resister that has several important attributes:
1) It "looks like" an antenna to the transmitter by presenting a 50-ohm impedence.
2) It has sufficient sufficient power handling capacity (e.g. 1W, 10w, 100W, 500W, 1500W).
3) The dummy load turns all power transmitted into it, into heat (i.e. no RF energy radiated).
|Heathkit Cantenna Dummy Load|