A method for operating an electromagnetic compatibility, EMC, testing system comprising: providing in an EMC test chamber an EMC antenna having a plurality of length-adjustable elements one of which is a driven element; selecting a plurality of frequencies within an EMC testing frequency range; separately for each of the plurality of selected frequencies, adjusting individually incrementally the lengths of each of the plurality of length-adjustable elements for selected combinations of length ratios between the driven element and other ones of the plurality of length-adjustable elements, including combinations of length ratios where the driven element is longer than the other ones of the plurality of length-adjustable elements; separately for each of the incremental lengths of each of the plurality of length-adjustable elements in the selected combinations of length ratios and for each of the plurality of selected frequencies, driving RF energy at the selected frequency at a calibration power level into the driven element of the EMC antenna and measuring VSWR and signal strength; separately for each of the plurality of selected frequencies, selecting and storing a one of the incremental lengths at a one of the selected combinations of length ratios having one of the lowest VSWR and a VSWR lower than a threshold value that exhibits a highest signal strength; placing an equipment under test in the EMC test chamber; separately for each of the plurality of selected frequencies: adjusting individually the lengths of each of the plurality of length-adjustable elements to the selected and stored lengths; driving RF energy at the selected frequency at a EMC test power level into the driven element of the EMC antenna to generate an e-field in the equipment under test; and measuring behavior of the equipment under test in the presence of the e-field. providing in an EMC test chamber an EMC antenna having a plurality of length-adjustable elements one of which is a driven element; selecting a plurality of frequencies within an EMC testing frequency range; separately for each of the plurality of selected frequencies, adjusting individually incrementally the lengths of each of the plurality of length-adjustable elements for selected combinations of length ratios between the driven element and other ones of the plurality of length-adjustable elements, including combinations of length ratios where the driven element is longer than the other ones of the plurality of length-adjustable elements; separately for each of the incremental lengths of each of the plurality of length-adjustable elements in the selected combinations of length ratios and for each of the plurality of selected frequencies, driving RF energy at the selected frequency at a calibration power level into the driven element of the EMC antenna and measuring VSWR and signal strength; separately for each of the plurality of selected frequencies, selecting and storing a one of the incremental lengths at a one of the selected combinations of length ratios having one of the lowest VSWR and a VSWR lower than a threshold value that exhibits a highest signal strength; placing an equipment under test in the EMC test chamber; separately for each of the plurality of selected frequencies: adjusting individually the lengths of each of the plurality of length-adjustable elements to the selected and stored lengths; driving RF energy at the selected frequency at a EMC test power level into the driven element of the EMC antenna to generate an e-field in the equipment under test; and measuring behavior of the equipment under test in the presence of the e-field. adjusting individually the lengths of each of the plurality of length-adjustable elements to the selected and stored lengths; driving RF energy at the selected frequency at a EMC test power level into the driven element of the EMC antenna to generate an e-field in the equipment under test; and measuring behavior of the equipment under test in the presence of the e-field.