High-Performance HF Loop Array: A DIY Receiving Antenna Project
Building a compact, high-performance two-element receiving loop array for 160m to 20m HF bands.
Description
Designing and constructing a two-element receiving loop antenna array for HF operation involves specific considerations for achieving high directivity and noise reduction. This resource details a homebrew system comprising two 30-inch diamond-shaped loops, spaced 20 feet apart, which are fed through mast-mounted preamplifiers and passive signal combiners. The operational principle relies on adjusting phase delays between elements via precise Belden 8241 coaxial cable lengths, optimized for specific bands from 160m to 20m. Performance data, derived from EZ-NEC modeling, illustrates consistent 90° azimuth-plane beamwidth and low take-off angles across the target bands, with Receiving Directivity Factor (RDF) values comparable to a 300-foot Beverage antenna.
The article presents detailed elevation and azimuth plots for 20m, 30m, 40m, 80m, and 160m, demonstrating the array's ability to provide strong response at low DX angles while also supporting NVIS signals. Key components like the DX Engineering RPA-1 preamplifier and DXE RSC-2 signal combiner are discussed, alongside the importance of impedance matching to preserve antenna patterns. The construction emphasizes self-contained elements that do not require ground radials, offering a compact solution suitable for suburban environments and stealth installations, with a focus on optimizing receive performance independently from transmit antennas.