Many years ago my dad brought up a new radar station at White Sands. It was a new design - a target tracking (automatic) radar.
Since the manufacture of the output tubes didn't want to drive the antenna when testing the transmitter and verifying specs.
It was determined that a number (N) 1000 watt light bulbs to be used.
That was great, the transmitter was harsh on start up currents and liked to over drive the filaments - new sets were pulled from stores every other day for several weeks. Then it stopped and the real antenna was attached for other tests. The purchasing guy had stocked up on a volume discount deal - and then found out the bulbs went back to the light poles.
Dummy loads are just an energy dump. The idea is to have the resistance near the value needed so to much current won't be drawn and not to high to prevent the power dump.
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