ETS-Lindgren's Model 3109 Biconical Antenna uses a modified Guanella balun for impedance transformation and matching. The Model 3109 provides a broad frequency range and because it is constructed of much heavier materials, it has a maximum continuous input power up to 1 kW, with a peak power handling capability up to 2 kW. While this antenna typically has a high VSWR at frequencies below 70 MHz, it is still capable of generating a high field strength with acceptable input power in this region of the band. The optional extended elements markedly improve its performance in this region. This antenna is ideal for IEC 1000-4-3 testing.
ETS-Lindgren is the only manufacturer to offer optional extended elements. These elements are twice as long as standard elements and enable users to generate high fields at low frequencies with less than 25% of the power usually required.