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Delta loop antennas for 40 meters plans and comparison of some models

A 2 element 40 meters band parasitic delta loop antenna project with pictures and details

Designing and constructing portable wire antennas for HF operations, this resource explores several configurations including the _foldback dipole_ for space-constrained setups and an inductively shortened dual-band dipole for 20m and 40m. It details the calculation of inductance for shortened elements, providing a Visual Basic 6.0 program screenshot that illustrates determining coil parameters like turns and length for a **25.5 uH** inductor. The document emphasizes practical considerations such as adjusting wire lengths for optimal SWR, noting that a dual-band dipole achieved SWR below 2:1 on both 20m and 40m, with careful adjustment bringing it under 1.5:1. Further, the resource describes a half-wave antenna matched with a coaxial stub, a method often referred to as the _Fuchskreis_ in German amateur radio circles, to transform the high feedpoint impedance to 50 Ohms. This monoband solution, for a 20m application, uses a stub length of **2.98m** (0.216 lambda multiplied by coax velocity factor) and a shorted stub of approximately 48cm. The coaxial stub design is highlighted for its resilience to ground proximity, allowing it to be rolled up or laid on the ground with minimal SWR impact, making it highly suitable for portable QRP operations.

This resource, originally intended to detail the technical specifications of the **Clover** digital communications mode, currently presents a "Page not found" error. The _Clover_ mode was designed for conveying 8-bit digital data over narrow-band high-frequency radio channels, offering robust performance under challenging propagation conditions. Its design focused on efficient data transfer and error correction, making it suitable for amateur radio operators seeking reliable digital links. The absence of the page prevents analysis of specific technical parameters, such as modulation schemes, data rates, or error correction codes that would have been presented. Historically, Clover offered significant advantages in throughput and reliability compared to earlier digital modes over HF, often achieving higher effective data rates than modes like PACTOR or AMTOR under similar signal-to-noise ratios. Without the content, a direct comparison of its performance metrics or practical application scenarios is not possible.

The page discusses the concept of a 2-element Parasitic Ground Plane antenna for the 40-meter band. It includes a conversation between amateur radio operators discussing modeling results and design considerations for the antenna. The author shares insights on radial configurations and the impact on antenna efficiency and pattern.

Building a Windom HF Antenna. A PDF file presentation about homebrewing a windom antenna for the HF bands with formulas for 40 and 80 meters bands and step by step guide on making a 4:1 balun to feed the antenna.

Presents SWR analysis of an **Alpha-Delta DX-LB Plus** multiband wire antenna, installed as an inverted-V at 40 feet with ends at 15 feet, using an RigExpert AA-54 analyzer. The resource provides a full SWR sweep from 0.1 MHz to 54 MHz, followed by detailed SWR graphs for individual amateur bands including 160m, 80m, 40m, 30m, 20m, 17m, 15m, 12m, 10m, and 6m. The analysis highlights the narrow bandwidth on 80m and 160m due to loading coils, necessitating tuning for specific operating frequencies. It notes excellent SWR performance across the entire 40m band and good results on 10m, also requiring tuning. The author shares personal experience with the antenna, including a 17,000 km QSO on 20 meters, and discusses plans to replace it with a homebrewed parallel **fan-dipole**.

A multi band portable link dipole antenna for 20 30 and 40 meters band

Constructing a mobile HF antenna presents unique challenges, particularly when aiming for multiband operation and robust mechanical stability. This project details N1GY's adaptation of the KM4IE $20 antenna and the _Texas Bugcatcher_ design, focusing on practical build considerations and on-the-road performance. The author shares insights from winding coils on 2-inch PVC forms and integrating a salvaged fiberglass core from an old Hamstick-style antenna to enhance structural integrity, preventing potential failures from stress on PVC joints. N1GY's build includes a custom matching coil and a commercially sourced MFJ loading coil, carefully integrated into the design. The article provides specific tap settings for bands from 75 meters to 15 meters, achieving SWRs as low as **1.2:1** on 40 meters and **1.6:1** on 75 meters. Mechanical testing involved driving at speeds up to 70 MPH on Interstate routes, confirming the antenna's durability and the effectiveness of its PVC brace system. Further modifications address real-world usability, such as simplifying antenna removal for car washes. The ground strap was updated with a Power Pole connector, and the brace attachment to the luggage rack was converted to wing nuts, reducing removal time from 30 minutes to approximately _five minutes_. This iterative design process highlights practical solutions for mobile HF operation.

An homebrew project of a full wave delta loop antenna for the 40 meters band with dimensione, picture and assembling instructions in Indonesian

An comprehensive article on 40 meters antenna comparing vertical height to the resulting gain

A vertical antenna project for the 7MHz made with some spare parts. Based on a broken 20 foot fishing pole, it is based on a good ground system made with radials and a capacitive hat done to increase the global radiation resistance of the antenna. A custom loading coil is also included in this project to perfectly tune the antenna to the CW portion of the 40 meters band.

Experimenting vertical wire antennas for 40 and 20 meters supported by balloons resulting in excellent gain in RX and good overall performance against horizontal dipole

During a club's "Filetto Day" event, a comparative field test was conducted between a **Buddipole** antenna and a homemade 20/40-meter wire dipole. The author, IW5EDI, performed this personal evaluation from a mountain top at 1500 meters above sea level, utilizing a Yaesu FT-857D transceiver to switch between antennas. The observations on the 20-meter band indicated that the wire dipole consistently delivered significantly stronger signals compared to the Buddipole. Additionally, the Buddipole exhibited higher levels of **QRM** during the listening tests. The commercial Buddipole, known for its multiband capability and compact size with a self-supporting tripod, was contrasted with the simpler, larger wire dipole, which required a fiberglass fish pole for support. This direct comparison highlights practical differences in performance and deployment between a popular portable commercial antenna and a basic wire antenna in a real-world operating environment.

Want to operate on 40 meters but only have a space a little over 16X16 ? Try this antenna.

Cushcraft A3S performances with the A743 kit to add 30 and 40 meters

Amateur Radio 40m 20m 15m Half Wave Fan dipole antenna project with part list, pictures and drawing. Includes the option to expand the antenna to cover the 80 meters band

N3OX three meters Flex Vertical, a Short, Frequency Agile Vertical for 40 meters

Constructing a 2-meter Moxon antenna for MURS channels, this resource details the antenna's geometry and expected radiation pattern. The design, optimized for low SWR, high gain, and front-to-back ratio on the first three MURS channels, uses 1/8-inch bronze brazing rod for elements. Author John E. Davis provides specific geometric parameters (A, B, C, D dimensions) rounded to the nearest 16th of an inch, along with a link to the final _.nec_ file for further analysis. Performance results show the attic-mounted Moxon performs well on the 2-meter band, despite its MURS optimization, with measured SWR plots provided. NEC-2 modeling predicts over 6 dBi gain and 40 dBi front-to-back ratio in free space. The author compares its directional performance to a _J-pole_ antenna, demonstrating substantially better signal strength for a nearby repeater when the Moxon is pointed in its general direction, confirming its superior gain and directivity.

Local amateur radio clubs often serve as vital hubs for hams to connect, share knowledge, and participate in group activities. The Orleans County Amateur Radio Club (OCARC), operating under the callsign WA2DQL, provides a focal point for amateur radio operators in Albion, New York, and the surrounding Orleans County area. These organizations frequently host events, offer technical assistance, and foster camaraderie among members, supporting various aspects of the hobby from contesting to emergency communications. OCARC's activities include discussions on proposed Technician class privileges for **80, 40, and 15 meters**, indicating an interest in regulatory changes affecting entry-level licensees. The club also promotes the use of online tools like _Radio Mobile Online_ for antenna pattern analysis and _VOACAP Online_ for propagation predictions, aiding members in optimizing their station performance. Furthermore, OCARC highlights participation in _Parks On The Air_ (POTA) events, such as the Erie Canal Bicentennial Celebration in 2025, encouraging outdoor operations and public engagement with amateur radio.

A dual band delta loop antenna resonating on 30 and 40 meters band using a single wire for the top slopers on both 30 and 40 meters and does not need any balun

The Buddipole Deluxe, a portable HF/VHF antenna system, receives a practical assessment from IW5EDI after a month of field use. The author, constrained by antenna restrictions, highlights the system's crucial role in enabling portable operations, even managing sporadic digital activity from a balcony. Direct comparisons to a fixed 3-band dipole reveal surprisingly comparable signal reports on 15, 17, and 20 meters, underscoring the Buddipole's effectiveness in real-world scenarios. Tuning the Buddipole proves straightforward on bands down to 20 meters, though the review notes significant challenges with SWR on lower bands like 40 meters, where achieving better than 3:1 SWR was problematic. Observations also include SWR variations with dipole rotation and mast height, suggesting environmental factors play a role. The overall manufacturing quality of the antenna and its accessories, including the tripod and carry bag, is deemed good, despite a minor issue with a pole connector. Looking ahead, the author plans to construct a homemade Buddipole version, possibly optimized for the 30-meter band, specifically for PSK31 operations from an apartment. This personal project reflects a common amateur radio practice of adapting commercial designs for specific needs, further extending the utility of portable antenna concepts.

A bazooka coax antenna for 40 meters band design by CA6TYS

About the Cushcraft A3S with A743 add-on for 30 an 40 meters

A dual band portable inverted V antenna for 80 and 40 meters band with dimensions for other bands and several assembling instruction

An easy to build and extremely high performance antenna, works perfectly on all HF bands 3.5-28 MHz with some compromises, it is basically an half wave dipole for 40-80 meters, an LC circuit or trap 40 meters allows you to use a single radiating element.

Presents a concise guide for Amateur Radio operators participating in Jamboree-on-the-Air (JOTA), an annual event connecting approximately 500,000 Scouts and Guides worldwide via ham radio. The resource details how to initiate a voice contact, including the use of "CQ Jamboree JOTA" and proper signal reporting with the RST system. It also outlines the typical exchange information, such as name, QTH, Scout rank, and age, encouraging participants to practice their responses. Authored by Bill Wetherill, N2WG, the brochure provides a practical phonetics chart and a comprehensive Morse code dictionary, including punctuation and prosigns like AR and SK. It clarifies rules for third-party operation under the direct supervision of a licensed operator, noting restrictions on international contacts without specific government agreements. Additionally, the guide lists recommended World Scout Frequencies for SSB and CW across 80, 40, 20, 17, 15, 12, and 10 meters, emphasizing courteous operating procedures. It includes a section on common Q-signals like QRM, QRN, and QSL, alongside the Amateur's Code, which stresses considerate, loyal, progressive, friendly, balanced, and patriotic conduct.

The resource provides coaxial cable attenuation data, listing signal loss in dB per 100 feet for various cable types across a frequency range from 1 MHz to 5.8 GHz. The initial table details attenuation for cables such as _RG-58_, _RG-8X_, and RG-213, with impedance values of 50 ohm or 75 ohm, at frequencies up to 1 GHz. For example, _RG-58_ exhibits **0.4 dB** loss at 1 MHz and **21.5 dB** loss at 1 GHz per 100 feet. A subsequent table expands on this data, including LMR series cables like _LMR-400_ and LMR-600, along with other types such as 9913F7 and RG214. This section covers frequencies from 30 MHz to 1,500 MHz, also noting the outer diameter of each cable. For instance, _LMR-400_ (0.405" diameter) shows **0.7 dB** loss at 30 MHz and 5.1 dB loss at 1,500 MHz per 100 feet. The final section focuses on VHF/UHF/Microwave amateur and ISM bands, presenting attenuation in dB per 100 feet (and meters) for frequencies including 144 MHz, 450 MHz, and 2.4 GHz. This table includes larger diameter hardline options like 1/2" LDF and 7/8" LDF, in addition to flexible coaxial cables. For example, 1/2" LDF cable demonstrates **0.85 dB** loss at 144 MHz and 6.6 dB loss at 2.4 GHz per 100 feet. DXZone Focus: Coaxial cable attenuation | LMR-400 | RG-58 | 5.8 GHz

Complete instructions on tuning the Butternut HF2V on four bands, 80, 40 , 30 and 15 meters

This wire antenna for 40 and 20 meter band feature a good SWR. Horizontal side of the antenna is placed at two meters above the ground. Impedance of the antenna are depending by the height of the base from the ground and conditions of the ground

The article, "Using 75 Ohm CATV Coaxial Cable," details methods for employing readily available 75-ohm CATV hardline in standard 50-ohm amateur radio setups. It addresses the inherent impedance mismatch and practical considerations, such as connector compatibility, for hams seeking cost-effective, low-loss feedline solutions. The resource specifically contrasts common 50-ohm cables like RG-8, RG213, and _LMR-400_ with 75-ohm hardline, highlighting the latter's lower loss characteristics, particularly at VHF and UHF frequencies. It explores two primary approaches to manage the impedance difference: direct connection with an acceptable SWR compromise and precise impedance transformation. The direct connection method acknowledges that a perfect 1:1 SWR is not always critical, especially when using low-loss coax. For impedance transformation, the article explains the use of half-wavelength sections of coax to reflect the antenna's 50-ohm impedance back to the transmitter, noting its single-frequency effectiveness. It also briefly mentions transformer designs using toroid cores and a technique involving two 1/12 wavelength sections of feedline for broader bandwidth. The content further clarifies the concept of _velocity factor_ for calculating electrical versus physical cable lengths, providing a generic formula for precise length determination. It notes that while half-wave matching is practical for 10 meters and above, it can result in excessively long runs for lower bands like 160 meters, potentially adding **250 feet** of cable. The article also mentions achieving a usable bandwidth of 28.000 MHz up to at least **28.8 MHz** on 10 meters with specific transformation techniques.

4 Square K9AY Array project for 80 and 40 meters band

Article about an end-fed anntenna for the 17 and 12 WARC Bands. 30 meters is not included in this project. This antenna includes a 14 windings unun impedance transformer using a FT-140-43 ferrite toroid, that should be enought for a 100W PEP.

Setting up a ZZ Wave antenna, a dual band loop antenna covering 80 and 40 meters.

Documents the construction of a **VHF/UHF** antenna addition for the Buddipole HF antenna system, leveraging the existing Versa-Tee component. The project details the fabrication of a custom antenna mount from angle aluminum, including specific drilling and tapping for 3/16"-24 bolts, and the creation of radials from Simpson Strong Tie Insulation Supports. It specifies radial lengths for 70 centimeters (6 inches from the center stud) and 2 meters (19 1/4 inches), noting the use of wire nuts for safety. The resource outlines the construction of a mast from 1/2" ID PVC conduit, connected with 3/8"-24 connecting nuts and bolts, mirroring the Buddipole's modular design. It describes the integration of a mobile dual-band antenna with a 3/8"-24 mounting stud and the custom coax setup with BNC and **PL-259** connectors. Field testing with an FT-817ND and a separate dual-band SWR meter confirmed good SWR on both 2 meters and the 440-450 MHz section of 70 centimeters, with positive reception reports during Field Day activities. Further, the article describes the creation of a custom carrying solution, including a 22-inch tripod bag and a fabric roll-up, to emulate the portability of the original Buddipole system.

The antenna in this project is a modification of the techniques used to design a multiband fan type dipole with little or no tuning involved having a total space of 105 feet

SWR analysis of an Alpha-Delta DX-LB Plus antenna, configured as an inverted-V with the apex at 40 feet and ends at 15 feet, reveals specific performance characteristics across the HF spectrum. Measurements were conducted using a RigExpert AA54 antenna analyzer, scanning from 0.100 MHz to 54.000 MHz to capture full-range SWR plots. The antenna exhibits notably narrow bandwidths on 80 meters and 160 meters, attributed to its loading coils, necessitating precise tuning for optimal operation within these bands. Conversely, the Alpha-Delta DX-LB Plus demonstrates excellent SWR across the entire 40-meter band, indicating a broad resonance. Performance on 10 meters also shows favorable SWR, though tuning to a desired operating frequency is still recommended for peak efficiency. The article details the methodology and tools employed, building upon a previous "Part 1" analysis of a G5RV antenna, providing a comparative context for antenna evaluation. Practical experience with this multi-band antenna, particularly its loading coil design, highlights the challenges in achieving desired SWR across all bands without specific adjustments. The author's subsequent plans involve replacing the Alpha-Delta DX-LB Plus with a homebrewed 80-40-20-10m parallel **fan-dipole**, aiming for improved resonant characteristics.

160 to 40 meters inverted L antennas projects

The resource examines the operational characteristics and potential of Moxon Yagi antennas, drawing insights from Les Moxon's work and subsequent NEC modeling. It presents simulated current distributions and radiation patterns for a 40-meter Moxon, comparing its performance against a standard 2-element Yagi on the same band. Specific data points include forward gain, front-to-back (F/B) ratio, and feedpoint impedance, which are critical parameters for antenna design and optimization. Further analysis extends to a 20-meter Moxon, detailing its gain, F/B ratio, and SWR bandwidth across the band. The discussion highlights the Moxon's compact footprint and its ability to achieve respectable performance metrics, making it a viable option for hams with limited space. The content provides a technical assessment of the Moxon's advantages in terms of pattern purity and impedance stability compared to other compact directional arrays. The article also touches upon the practical considerations for constructing and deploying Moxon antennas, emphasizing the trade-offs between physical size and electrical performance. It includes graphical representations of antenna currents and radiation patterns, offering visual aids to understand the theoretical concepts discussed.

YU7EF 8 elements yagi antenna for 4 meters band

A monoband delta loop antenna for the 7 MHz. This vertically polarized DX Antenna is a full wavelength sngle side antenna and has a total length of 42.3 meters (137,1 inch) Can be easily setup with a flag pole or fishing pole as center top mast. For optimal performance lower side should be at 2 meter above the ground. This antenna offers a low radiation angle and 1 DB Gain.

Complete collection of the four main parts of this excellet research on modelling and designing half wave dipole antennas for 40 meters band, covering all aspects beginning from full wave length antennas, to shortened, loaded and reshaped dipoles

A dual band dipole antenna for 40 and 80 meters band. Total lenght of 26 meters, foreseen two coils at aprox 11 meters distance from center feed.

Fifty-three digital modes, including PSK31, RTTY, and JT65, are explored in this resource, providing detailed descriptions of their underlying technologies and typical use cases. It covers error correction methods like ARQ in PACTOR and FEC in JT65, alongside modulation schemes such as FSK and PSK. The content highlights the evolution of digital communication from traditional TNC-based systems to modern sound card implementations, emphasizing the role of personal computers in advancing these modes. Specific modes like AMTOR, PACTOR, and G-TOR are discussed, noting their baud rates and error correction capabilities. For instance, AMTOR operates at 100 baud, while PACTOR offers 200 baud with Huffman compression. The article also delves into newer modes like MFSK16, which uses 16 tones and continuous Forward Error Correction, and Olivia, capable of decoding signals 10-14 dB below the noise floor. Each mode's bandwidth, speed, and resilience to propagation challenges are examined, such as MT63's 1 KHz bandwidth and 100 WPM rate, or Hellschreiber's 75 Hz bandwidth and 35 WPM text rate. The resource also lists predominant USA HF digital frequencies for bands like 160, 80, and 40 meters, specifying segments for PSK31, RTTY, SSTV, and Packet. It includes links to freeware and shareware sound card software such as Digipan, FLDigi, and MixW, enabling amateurs to experiment with these modes.

A multiband Fan Dipole that works on 40 20 15 meters band, making a folded dipole for 7 MHz band and additional element for the 21 MHz and 14 MHz

Full article on how to build a home-made wire dipole antenna for 40 and 80 meters band. Article is fully in italian, as it was published on ARI RadioRivista, but is plenty of self explaining pictures that will guide you on homebrewing this trapped dipole antenna for the lower amateur radio bands.

Roach pole vertical antenna for 40 and 30 meters band featuring good performance on short skips contacts compared to wire dipole

This article is about a home made project of a whip antenna for 2 meters band. Includes lenght of whip for all frequencies from 140 MHz to 151 MHz both in mm and inches

An antenna for 80 meters band for those who does not have enough space to setup a halwave wire dipole that is aprox 130ft or 40 meters. The antenna is an open-wire-fed shortened dipole

An inverted V Dipole antenna for HF bands, working on 10 20 40 and 80 meters band. PDF Presentation