Why A Beverage is a long wire (one wavelength or more) strung low over ground, and it responds to waves traveling along it from either end. Placing a resistor roughly equal to the wire's characteristic impedance (typically 400 to 600 ohms) at the far end, to ground, absorbs the energy picked up from signals arriving off that end instead of letting it reflect back down the wire. The result is a unidirectional pattern with good front-to-back ratio, which is what makes terminated Beverages so useful for low-band receiving.