Conical Log Spiral Antennas are made with spiral windings of coaxial cable attached to the outside of a fiberglass cone.

Outside windings improve heat dissipation. This cone is attached to a delrin rod equipped with an aluminum base. The antenna mount base accepts standard 1/4 in x 20 threads from a tripod.

Once used exclusively for MIL-STD and SAE testing, conical log spiral antennas are effective for other types of measurements too. 

For example they can be used for close-in quick-looks to find the spectral characteristics of RF emissions. 

For immunity testing, conical log spirals generate reasonable field strengths with modest power input. 

By placing conical log spiral antennas in a vertical position with respect to the ground plane, they can also be used as omni-directional, horizontally polarized antennas for electromagnetic site surveys.