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An FCP is not magic. It has no gain. An FCP improves an antenna system by replacing more loss with less loss. Some have been able to erect better wires in the air because the small size of the FCP allowed better placement of the antenna.

Constructing a dual-band antenna for 40 and 20 meters often involves compromises in size or complexity. This resource presents a compact _open sleeve dipole_ design that addresses these challenges by using 450-ohm ladder line and folded elements to achieve a total length of approximately **17.17 meters**, significantly shorter than a full-size 40-meter dipole. The design leverages electromagnetic coupling, where a primary radiator handles the 40-meter band, and a second conductor resonates on 20 meters without direct electrical connection. This configuration eliminates the need for traditional traps, loading coils, or switching components, simplifying construction and reducing potential loss points. The antenna is fed with RG-58C/U coaxial cable, and a common-mode choke is recommended at the feed point to suppress sheath currents, ensuring a cleaner radiation pattern and minimizing RF in the shack. The design is well-suited for portable operations, field deployments, temporary installations, and restricted urban environments where space is a premium, offering solid performance on both HF bands.

A W8JK/Moxon antenna variant with 400cm long monopoles is detailed, demonstrating a **1dbd** gain improvement over the traditional Open-Folded W8JK. This design, relying on the _Moxon principle_, achieves higher radiation impedance, leading to increased antenna efficiency and reduced losses. The article includes VNA output data for various HF bands, showing impedance characteristics from 10.1 MHz to 50.1 MHz, and provides NEC model wire definitions for the antenna structure. Field tests performed by F6IIV, Marc, compared his W8JK Moxon style antenna against a Cobweb antenna at the same height. Results indicated the W8JK Moxon variant provided a **6dB** (1 S-meter point) advantage on most bands from 20m to 10m, and a significant 10dB (1.5 S-meter points) advantage on 15m. The antenna features a 2.70m boom and a turning radius of less than 3 meters, making it suitable for limited space installations while maintaining bi-directional performance on most bands.

This document provides a detailed guide on constructing and mounting a folded dipol for the 146 MHz frequency in a vertical configuration to be used in Yagi antennas. The step-by-step instructions and diagrams included make it easy for hams to build and set up this type of antenna. Understanding and implementing this design can enhance the performance of radio communication for Amateurs operating in the 2-meter band. Whether you are looking to improve your signal strength or experiment with antenna designs, this resource offers valuable insights and practical information.

Originally designed by John Kraus, W8JK in about 1940, this antenna has some interesting properties. The W8JK antenna is 2 (Two) centre-fed double-dipole fed by a pair of anti-phase signals. Small size, simple antenna, offer nice performance but need a tuner. Tested in this project from 30m to 6m bands

Learn how to design and analyze a folded trifilar antenna for the 80-meter band. Based on a description from RAF antennas between 1940 and 1970, this article provides step-by-step guidance on modeling the antenna, calculating resonance frequency, adjusting dimensions, and verifying performance. Perfect for hams looking to improve their antenna setup for better transmission and reception on the 80M band.

Steve Nichols, G0KYA, presents a practical examination of ground systems for vertical antennas, drawing heavily on the empirical research of Rudy Severns, N6LF. He explains that a robust radial field is crucial for ground-dependent verticals, effectively replacing the antenna's "missing half" and mitigating severe RF absorption in lossy soil. Nichols clarifies that surface radials do not strictly require a quarter-wavelength; instead, deploying a minimum of 16 to 32 shorter wires often yields superior results compared to fewer, longer ones. The presentation also addresses the common SWR paradox: a poor ground might show a perfect 1:1 match, but adding radials, while potentially raising the SWR to around 1.4:1, significantly improves true radiation efficiency. Nichols defines counterpoises as elevated wire networks that substitute for earth connections, offering solutions for limited-space installations, such as the **Folded Counterpoise (FCP)** for 160 meters. This resource provides actionable engineering data for optimizing vertical antenna performance.

This article presents the C-Pole antenna project, a compact, ground-independent vertical antenna designed for amateur radio operators. It features a folded half-wave dipole configuration that eliminates the need for radials, making it suitable for various locations, especially in deed-restricted areas. The C-Pole offers efficient performance with a 2:1 SWR bandwidth of approximately 3%, and it can be easily constructed using common materials. Additionally, the article discusses practical aspects such as feed-point impedance transformation and balun design to optimize functionality and minimize losses.

Online antenna calculator for a basic 3 elements yagi uda directional antenna. The described antenna design offers a front-to-back ratio of at least 20 dB, a gain exceeding 7.3 dBi, and a bandwidth (SWR < 2) of approximately 7% around the center frequency. It has an input impedance of 50 ohms when using a straight split dipole, which can be substituted with a folded dipole of the same length, increasing the impedance to 200 ohms. A matching balun is required for coaxial feeder connection, and the boom should be made of a dielectric material, like wood.

The article describes the construction of a Lindenblad antenna, which is well-suited for receiving signals from low-orbiting weather satellites. The key points are: The Lindenblad antenna has an omnidirectional horizontal radiation pattern and is optimized for low to medium elevation angles, making it ideal for tracking passing satellites near the horizon. It is designed to receive circular polarization, which is common for weather satellite signals. The antenna is constructed using 4 folded dipole elements arranged on a cross-shaped frame. The necessary materials include a plastic junction box, PVC tubing, and aluminum rods to form the dipole elements. The article provides detailed instructions for preparing the components, assembling the dipoles, and connecting the feed lines to create the complete antenna. The completed antenna can be mounted on a vertical support, with the dipole elements angled at 30 degrees from horizontal, to optimize reception of the passing satellites. The author notes that the design was originally published in a now-defunct magazine, Meteo Satellite Inf", in 1993

The Slim Jim VHF antenna, originally designed by G2BCX, is a folded half-wave dipole fed by a quarter-wave matching section. This version, built from a recycled professional aluminum dipole, demonstrates that various materials—such as copper, brass, or twin-lead—can be used. The article details the antenna’s construction, required materials, and tuning process, emphasizing mechanical stability and ease of assembly. With proper adjustment of the feed point, it provides excellent SWR across the band. Its durability and simplicity make it a practical and efficient VHF antenna solution.

WB5NHL describes setting up a 160-meter antenna on a small suburban lot, where standard options like Beverage antennas and 1/4 wavelength verticals require extensive space and ground systems. Instead, Guy Olinger's Folded Counterpoise (FCP) provides a solution. The FCP minimizes ground losses by using a folded wire design, allowing effective antenna placement in limited space. The FCP, fed with an isolation transformer, enabled WB5NHL's first 160-meter antenna installation, offering improved performance despite space constraints.

The article by Guy Olinger, K2AV, published in the May/June 2012 National Contest Journal, introduces the Folded Counterpoise (FCP), a compact 516-foot single-wire counterpoise elevated at 8 feet, designed for 160-meter operations on small lots like 100x150-foot backyards. Originating from efforts to revive Top Band for W0UCE on a postage-stamp property, the FCP uses strategic folds to cancel ground fields within 33 feet of center, minimizing losses to 0.13-0.53 dB—outperforming sparse or on-ground radials by up to 15 dB in poor soil—while mimicking opposed radials for efficient feedpoint impedance. Paired with a critical 1:1 or 4:1 isolation transformer (e.g., trifilar on T300-2 toroid) to block common-mode currents on coax feeds, it delivers proven results: K2AV's #8 North America low-power contest score, 7+ dB gains at W4KAZ and K5AF, and over 10,000 global web hits for DIY instructions using bare 12 AWG wire and weatherproof enclosures. Ideal for acreage-challenged hams, the FCP also excels on 80 meters with scaled dimensions, offering a low-loss alternative where full radials are impractical

Fully functional weathervane conceals an efficient 2- meter base-station antenna. Your Neighbors and HOA won’t know it’s there and they will love the rooster-vane. The Rooster-Tenna is a covert 2-meter ham radio antenna disguised as a functional weathervane, ensuring seamless integration into residential environments. This improved version features a wide-spaced parallel-fed folded dipole in a compact skeleton slot design. Constructed from aluminum tubing and acrylic supports, it offers omnidirectional, vertically polarized performance suitable for repeater and satellite use. Easy to mount and tune, it achieves a low SWR across the 2m band. With 3D-printable parts available, the Rooster-Tenna blends practicality with stealth, making it an ideal solution for HOA-restricted areas

The Zeppelin antenna, a J-type design, is presented as a two-band HF dipole, offering independent operation on harmonically related frequencies. This resource details its electrical configuration, comprising a half-wave radiator end-fed by a quarter-wave matching section, and explores its historical evolution from early Zeppelin airship applications to modern amateur radio use. The article specifically examines how a Zepp antenna tuned to 28.4 MHz (10 meters) exhibits a harmonic relationship with 15.4 MHz (20 meters), noting a frequency ratio of approximately 1.84:1, which deviates from a perfect 2:1 due to factors like elevation, wire separation, velocity factor, and end-effect. Antenna modeling results, including SWR sweeps at 28.4 MHz (1.1 SWR) and 15.4 MHz (1.6 SWR), are provided through Graph 1 and Graph 2, illustrating the antenna's performance across these bands. Current distribution patterns for both the 28.4 MHz (second harmonic) and 15.4 MHz (first harmonic) operations are visually represented in Figure 2 and Figure 3, respectively. The author also includes a 4NEC2 model's "Symbol Conversion file" definitions and calculated #14 wire dimensions for achieving resonance at 28.4 MHz, with the antenna positioned at a height of 33 feet. The discussion further highlights the antenna's versatility, suggesting its potential as a single-band, center-fed, 15.4 MHz half-wave folded end dipole when fed at a specific low current point. This analysis provides practical insights into constructing and optimizing a multi-band Zepp antenna for HF operations, emphasizing its unique harmonic characteristics and physical compactness.