Abstract: A broadband frequency meter probe utilizes a high frequency antenna and a low frequency antenna to sense wideband electromagnetic energy wherein the different frequency band antennas are closely based monopole and disk antennas. A three-dimensional probe is disclosed having three mutually orthogonal antenna pairs. Damping is provided to decouple resonance which would otherwise occur between the monopole and disk antenna. Self-checking for sensing operation of associated electronics and for providing an indication of normal and abnormal operating conditions is included.