The device was originally given the name "carcinotron", after the Greek name for the
crayfish, which swim backwards. By simply changing the supply voltage, the device could produce any required frequency across a band that was much larger than any existing microwave amplifier could match - the
cavity magnetron worked at a single frequency defined by the physical dimensions of their resonators, and while the
klystron amplified an external signal, it only did so efficiently within a small range of frequencies. Previously, jamming a radar was a complex and time-consuming operation. Operators had to listen for potential frequencies being used, set up one of a bank of amplifiers on that frequency, and then begin broadcasting. When the radar station realized what was happening, they would change their frequencies and the process would begin again. In contrast, the carcinotron could sweep through all the possible frequencies so rapidly that it appeared to be a constant signal on all of the frequencies at once. Typical designs could generate hundreds or low thousands of watts, so at any one frequency, there might be a few watts of power that is received by the radar station. However, at long range the amount of energy from the original radar broadcast that reaches the aircraft is only a few watts at most, so the carcinotron can overpower them. The system was so powerful that it was found that a carcinotron operating on an aircraft would begin to be effective even before it rose above the
radar horizon. As it swept through the frequencies it would broadcast on the radar's operating frequency at what were effectively random times, filling the display with random dots any time the antenna was pointed near it, perhaps 3 degrees on either side of the target. There were so many dots that the display simply filled with white noise in that area. As it approached the station, the signal would also begin to appear in the antenna's
sidelobes, creating further areas that were blanked out by noise. At close range, on the order of , the entire
radar display would be completely filled with noise, rendering it useless. The concept was so powerful as a
jammer that there were serious concerns that ground-based radars were obsolete. Airborne radars had the advantage that they could approach the aircraft carrying the jammer, and, eventually, the huge output from their transmitter would "burn through" the jamming. However, interceptors of the era relied on
ground direction to get into range, using ground-based radars. This represented an enormous threat to air defense operations. For ground radars, the threat was eventually solved in two ways. The first was that radars were upgraded to operate on many different frequencies and switch among them randomly from pulse to pulse, a concept now known as
frequency agility. Some of these frequencies were never used in peacetime, and highly secret, with the hope that they would not be known to the jammer in wartime. The carcinotron could still sweep through the entire band, but then it would be broadcasting on the same frequency as the radar only at random times, reducing its effectiveness. The other solution was to add passive receivers that triangulated on the carcinotron broadcasts, allowing the ground stations to produce accurate tracking information on the location of the jammer and allowing them to be attacked.{{cite encyclopedia == The slow-wave structure ==