The EM-6874 Loop antenna is nominally used 20 Hz to 30 MHz and is designed for uncalibrated substitution measurements of shielding effectiveness as described by MILSTD-285, IEEE STD 299, and NSA-65-6.

The antenna has a radiating element consisting of a single turn loop 0.3 meter in diameter, making the antenna capable of operating at very high loop currents without damage. In addition, a Type N connector is used which also permits high input levels to be applied to the antenna.

Although uncalibrated, the field strength generated is approximately 2.7 mA/meter/ Ampere. The antenna impedance may be approximated by series combination of a 600 nH and a resistance less than 1 ohm. Its signal handling capability is on the order of 1 kV peak and 40 Amperes RMS.

CAUTION: Since this antenna does not provide a 50 ohm load to the instrument driving it, some amplifiers or generators may be damaged if they are not capable of driving a 600 nH load.