Due to its small size and low weight, the Rohde & Schwarz HE 100 Active Directional Antenna 20 MHz - 1 GHz in conjunction with a compact, portable receiver is ideally suited for tracing signal sources and sources of interference. The direction of the signal source is found by pointing the antenna towards the direction of maximum signal voltage. The overall frequency range from 20 MHz to 1000 MHz is covered by three exchangeable antenna modules, which handle both vertically and horizontally polarized signals and have almost identical cardioid radiation patterns in both planes. The broadband, cardioid directional pattern of the HE 100 is obtained by using loaded loop antenna modules of different size for the three sub-ranges of 20 MHz to 200 MHz, 200 MHz to 500 MHz and 500 MHz to 1000 MHz.
- Power supply, which comes from a set of four round cells R6 (dry or NiCd cells) contained in a removable battery holder.
- Antenna electronics, comprising RF amplifier, active/passive switch and circuitry for the meter.
- Meter, which indicates the strength of the incoming signal. The pointer deflection is controlled by the receiver via the RF cable. The meter, which can be illuminated, also indicates the state of the batteries at the push of a button.