Random Wire / Long Wire Antenna (Homebrew Design)
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| Frequency | 1.8-30 MHz (multiband with tuner; non-resonant) |
| Modes | SSB, CW, AM, digital |
| Connector | binding-posts or SO-239 via balun |
| Year | 1900 |
| feedpoint | binding-posts or SO-239 via balun |
The oldest antenna design in amateur radio. Literally a wire thrown over a tree or strung between supports. Works on multiple bands with a tuner. Cheap. Quick to deploy. No engineering required. The antenna that has made more contacts than any other design in radio history.
Requires a tuner on almost every frequency. Feed line radiation. Unpredictable impedance. Performance varies by length, height, routing, and ground conditions. Not resonant on any specific band unless accidentally. RF in the shack is common without a proper matching unit.
The first antenna and still the most common. Every ham operator has put up a random wire at some point, usually as a temporary solution that becomes permanent. A long wire antenna tuned with a good matching unit is far more capable than its reputation suggests.
A long wire is the simplest HF antenna there is: a single length of wire, end-fed, run as high and as straight as you can manage. Strictly speaking the term 'long wire' means a wire at least one wavelength long, though in casual use it covers almost any random-length end-fed wire. Its appeal is obvious; it is cheap, easy to put up, and with an antenna tuner (and usually a good ground or counterpoise) it can be made to load on many HF bands.
The trade-offs are equally real. A random-length wire is not resonant, so it needs a tuner to present a usable match, and it relies on a solid RF ground or counterpoise to work against. As the wire gets longer relative to the wavelength, its radiation pattern breaks up into multiple lobes pointing in various directions, which can be an advantage or a frustration depending on what you are trying to work. It is a workhorse for simplicity rather than a precision instrument.
It is a timeless do-it-yourself design. For a resonant, tuner-free end-fed instead, the end-fed half-wave is the modern refinement, and the G5RV is a center-fed multi-band wire alternative.