ETS-Lindgren's Model 3301C Active Monopole Antenna is designed to provide reception of an electric field throughout its frequency range, in a single band, without tuning or bandswitching. The 3301C Active Monopole Antenna factor 3 dB roll-off points are at 170 Hz and 30 MHz. Between 250 Hz and 20 MHz, the antenna factor is flat within +/- 1 dB. To prevent saturation by the low frequency signals, the lower 3 dB point is switch-selectable at 170 Hz, 1.9 kHz or 22 kHz. The 3301C is able to sense fields of +7 dB (uV/m) at 1 MHz with a 1 kHz bandwidth. Saturation will not occur below a field strength of 0.8 V/m, resulting in an extremely wide dynamic range to 141 dB. The saturation indicator alerts you of the need to use the internal attenuators.
The model 3301C antenna consists of an stainless steel rod, a counterpoise 61 cm x 61 cm (24 in x 24 in), a broadband high input impedance amplifier built into the base, and an AC power adapter for battery charging (nominal 90 to 265 VAC, 50/60 Hz). The front panel contains controls and indicators include a power switch and power-on indicator, a receptacle and indicator for the battery charger, a grounded female BNC output connector and a signal saturation indicator. Power is supplied by internal AA size rechargeable nickel-metal hydride batteries.