The transmit loop antenna HFRA 5159 was designed to generate well defined magnetic fields in the frequency range from DC to 400 kHz. With slightly reduced performance the loop can be used in the frequency range up to 2 MHz. The loop, consisting of 28 turns, is shielded against E-fields. The nickel-plated brass housing contains resistors to verify the loop current by voltage measurement.The loop antenna has a flat frequency response over the entire frequency range. The loop can mounted at its female large camera thread.
The generated magnetic field is proportional to the loop current. A tabular indicates the fieldstrength values in A/m and dBμA/m to be expected with the loop current of 100 mA. Additionally the relative decrease of magnetic fieldstrength referred to the center of the loop antenna can be found. Lower magnetic fieldstrengths can be achieved by scaling the current to the respective value. With a feed current of 10 mA instead of 100 mA the tabular values decrease by a factor of 10, which corresponds to a reduction by 20 dB in logarithmic measure. All specified magnetic fieldstrengths refer to the component which is perpendicular to the loop-plane.