ETS-Lindgren 3101 Conical Log Spiral Antenna 200 MHz - 1 GHz

The Model 3101 Conical Log Spiral is 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.