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Random wire antenna Improved random wire antenna Static discharge unit 9:1 transformer DX 390 mute modification Attenuator
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This is probably the oldest SWL antenna design. It is often called a "long wire" though a true long wire is cut to a specific frequency and is at least one wave length long at that frequency. A random wire, on the other hand, is generally cut to no specific length and is intended to cover a wide range of frequencies. The flat top section can be about any length but is usually from forty to one hundred feet long. It can be made of just about any conductive wire but copper is preferred due to it's high conductivity and easy solder ability. Wire diameter is rather insignificant. It can be made from thin magnet wire or welding cable. The only real concern with wire size is physical strength. This antenna works quite well but does have one major drawback. Since the lead-in wire is not shielded, it forms part of the antenna and if run through any high noise fields, it will conduct this noise into your receiver. Since most households have appliances that generate considerable noise this can be a problem. If your circumstances are such that local noise is not a problem, this antenna is cheap, easy, and effective. In any case, a static discharge unit should be used to drain static from the antenna and protect the radio.