CHA SKYLOOP 40

CHA SKYLOOP 40 Full-Wave Loop Performance in a Practical 40-Meter Footprint The CHA SKYLOOP 40 is a full-size horizontal loop antenna engineered for operators who want excellent HF performance, quiet reception, broad radiation coverage, and dependable multiband operation without the enormous installation area required by larger full-wave loops. Constructed from 141 feet of rugged 16-gauge wire, the antenna provides operation across the entire 40- and 20-meter amateur bands without an antenna tuner when properly installed and adjusted. When used with a suitable antenna tuner, it also supports the 17-, 15-, 12-, and 10-meter bands, creating a highly versatile six-band antenna system for home stations, base camps, emergency communications, and shortwave listening. An integral broadband 2.5:1 matching transformer provides the impedance transformation required to connect the loop to a standard 50-ohm coaxial feed line. The matching unit is equipped with an SO-239 connector, secure wing-nut wire terminals, an integrated support eyebolt, strain-relief hardware, and a ground connection. Designed for Real-World Installations When installed as a square, each side of the CHA SKYLOOP 40 is approximately 35¼ feet long. However, a perfect square is not required. Individual sides may be made longer or shorter to accommodate available trees, masts, fence posts, building attachment points, or other safe supports, provided the total loop length remains approximately 141 feet. This flexibility makes the CHA SKYLOOP 40 an excellent choice for: Home and base stations Smaller properties where a larger loop will not fit HOA-conscious and visually discreet installations Emergency and disaster communications Base-camp and semi-permanent field stations Regional and long-distance HF communications Near-Vertical Incidence Skywave communications Shortwave and general-coverage listening The lowest recommended optimal installation height is approximately 30 feet, although the antenna can still provide excellent results when installed lower. Raising the loop generally improves efficiency and supports broader regional and long-distance communication. A lower horizontal installation emphasizes the high-angle radiation useful for NVIS communications, particularly on 40 meters. Actual performance will vary with installation height, loop shape, ground conductivity, surrounding objects, terrain, feed-line routing, propagation conditions, and station configuration. Quiet Reception and Broad Coverage Horizontal full-wave loops are widely valued for their relatively quiet receive characteristics. Because the antenna forms a closed-loop structure, it can often receive less locally generated electrical noise than many open-ended wire antennas. The CHA SKYLOOP 40 also provides a broad radiation pattern, making it useful for communicating in several directions without requiring an antenna rotator. Its radiation characteristics change with frequency and installation height, allowing the same antenna to support regional, NVIS, and longer-distance communications. Multiband Operation The CHA SKYLOOP 40 is designed to operate on: Without an antenna tuner 40 meters: 7.0–7.3 MHz 20 meters: 14.0–14.35 MHz With a suitable antenna tuner 17 meters: 18.068–18.168 MHz 15 meters: 21.0–21.45 MHz 12 meters: 24.89–24.99 MHz 10 meters: 28.0–29.0 MHz Always verify the completed installation with an antenna analyzer or SWR meter before transmitting. Installation height, ground conditions, nearby structures, vegetation, conductive objects, and loop geometry can affect resonance and impedance. The Antenna System Consists Of: CHA SKYLOOP 40 Matching Transformer Unit containing the integral broadband 2.5:1 matching transformer 141-foot 16-gauge Loop Wire assembly Line Winder for storing and transporting the loop wire Stainless-steel carabiners for attaching the loop-wire ends and providing strain relief Integrated support eyebolt on the Matching Transformer Unit Isolation rings for electrically isolating, supporting, and forming the corners of the loop Spade lugs installed on the loop-wire ends for connection to the matching unit Wing-nut loop-wire terminals on the Matching Transformer Unit SO-239 coaxial connector Ground connection End Insulator Strip for controlled antenna-length adjustment Extra spade lugs and heat-shrink tubing for field tuning Official CHA SKYLOOP 40 User Guide and installation instructions Additional Equipment Required The following installation equipment is not part of the basic antenna system and must be selected according to the installation site: Four safe and mechanically suitable support points Paracord or another appropriate nonconductive support line 50-ohm coaxial cable terminated with a PL-259 connector Weatherproof coaxial-connection sealant Antenna analyzer or SWR meter Suitable antenna tuner when operating on 17, 15, 12, or 10 meters Appropriate lightning protection and station-grounding equipment for a permanent installation Available recommended accessories include CHA COAX CABLE with an integrated RFI choke and the CHA PORTA-MAST for suitable home or semi-permanent installations. Installation and Tuning The CHA SKYLOOP 40 is manufactured at a length intended to resonate near the lower CW and digital portion of the 40-meter band. Because every installation environment is different, the completed antenna should be measured before making any adjustments. If the installed SWR is 2.0:1 or lower at both 7.000 and 7.300 MHz, no trimming is normally required. If the SWR is lower at the bottom of the band and rises above 2.0:1 toward 7.300 MHz, the loop may be electrically too long for the desired operating range. The antenna can then be shortened carefully using the supplied End Insulator Strip, additional spade lugs, and heat-shrink tubing. As a general field estimate, removing one foot of wire may raise resonance by approximately 60 kHz, but the actual change will depend on the installation. Trim only in small increments and remeasure after every adjustment. Wire that has been removed cannot easily be restored. Specifications Antenna type: Horizontal full-wave loop No-tuner frequency coverage: 7.0–7.3 MHz and 14.0–14.35 MHz Tuner-supported frequency coverage: 18.068–18.168 MHz, 21.0–21.45 MHz, 24.89–24.99 MHz, and 28.0–29.0 MHz Maximum power – SSB: 500 watts Maximum power – CW: 250 watts Maximum power – Digital modes: 100 watts Matching transformer: Integral broadband 2.5:1 transformer RF connection: UHF female connector, SO-239 Loop wire: 16-gauge wire Military KEVLAR Breaded Wire PTFE Total loop length: 141 feet Nominal square dimensions: Approximately 35¼ feet per side Minimum 2:1 SWR bandwidth: 350 kHz SWR: Less than 2.0:1 at resonance Lowest optimal installation height: Approximately 30 feet Weight: 2 pounds, 8 ounces Colors: Gray, black, and green A Serious HF Antenna Without an Enormous Footprint The CHA SKYLOOP 40 combines the operational benefits of a horizontal full-wave loop with a footprint that can fit many real-world properties. It provides no-tuner operation on two of the most popular HF bands, tuner-assisted access to four additional bands, substantial power-handling capability, flexible installation geometry, and strong regional, NVIS, and long-distance communication potential. For operators seeking a rugged, quiet, and versatile wire antenna for home, field, emergency, or listening applications, the CHA SKYLOOP 40 delivers full-size loop performance in a practical and adaptable antenna system.