The Huygens Box (HB) technique offers an accurate and computationally efficient approach for antenna placement within computational electromagnetic solvers. This paper presents an experimental validation of the HB method for low-frequency, flush-mounted antennas using measured radiation patterns of a monocone antenna mounted on a 4-meter ground plane, acquired with a multi-probe system. The Infinite Plane Boundary Condition (IPBC) pre-processing is applied to minimize edge diffraction effects from the finite ground plane. The HB model is integrated onto an aircraft geometry and evaluated using full-wave simulations across the 100–200 MHz band. Results show strong agreement with reference data, confirming findings from a recent parametric study on HB dimensioning for low-frequency measured sources. Repeating the analysis with the known CAD model of the source shows minimal deviation from measured data, demonstrating robustness against typical low-frequency measurement errors. These results confirm the HB method as a reliable tool for low-frequency antenna modeling.