The active loop antenna HLA 6121 is designed for operation in the frequency range 9 kHz to 30 MHz. It is ideally suited for magnetic field measurements as required by several standards (e.g. CISPR 11, CISPR 16-1-4, CISPR 16-2-3, FCC 18 and others). The built-in preamplifier matches the extremely low impedance of the loop to the measuring receiver. The HLA 6121 has a constant factor over the whole of its frequency range, making it ideal for swept measurement systems. The antenna is powered by an external DC supply like the EMI receiver’s transducer supply, battery pack or with the included power supply unit PSU 6001. The delivery of the HLA 6121 includes an adapter which offers the DC supply of the HLA 6121 via the coaxial cable. It allows most flexible operation and the location of the power supply unit outside the chamber.