The AM-741R Active Monopole Antenna is used for radiated emissions measurements, typically below 30 MHz. It is commonly used for tests according to RE102 of MIL-STD-461, Section 21 of RTCA DO-160, CISPR 25 (automotive), and other various standards. It is required per most test procedures, that the counterpoise be bonded directly to the ground plane on (or over) which the Equipment Under Test (EUT) is installed.
However, per the latest revisions of MIL-STD 461, the antenna may only be grounded through the shield of the output cable via a metallic bracket bonded to the chamber floor, directly below the antenna. It also specifies that the output cable be fitted with a ferrite, centered between the bracket and antenna output, having an impedance of 20-30Ω at 20 MHz. Com-Power’s AMS-741 Monopole Grounding Kit, which includes the output cable (with ferrite), elbow adapter and grounding bracket, is available separately.