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This calculator is designed to give the vertical length of a quarter-wave ground plane antenna, and the length of each of the four radials for the selected frequency you have entered

Sherwood Engineering Inc. (SEI) offers a repository of technical presentations and white papers focused on optimizing amateur radio transceiver and receiver performance. Content includes detailed analyses of _roofing filters_, transmitted IMD, and receiver characteristics, with specific discussions on products like the Drake R-4C and Icom IC-781. Presentations from events such as Dayton Contest University (2008-2014) cover topics like "How To Optimize Rig Performance," "Transceiver Performance: 10 Years of Change," and "Choosing a Transceiver: Far from Simple." Additional white papers address HF mobile antenna efficiency, ground screen alternatives to buried radial systems, and common receiver problems with solutions. The site also provides historical product information for items like the SE-3 MK IV synchronous AM detector and various 455 kHz mechanical and crystal filters, though many products are no longer in production. Receiver test data and alignment tips for the R-4C are also available, offering insights into rig modifications and performance enhancements.

The grounded half loop describe in this article is basically a half wave length wire on 80 Meters. The 80M grounded half loop antenna, inspired by a 1984 QST article by SM0AQW, is a compact solution for limited spaces. Comprising a 127-foot wire fed against ground and supported by radials, it balances performance and practicality. Despite compromises in length and proximity to structures, the antenna delivers strong signal reports and effective multi-band tuning using an SGC 237 antenna coupler. Ideal for CW operation, it offers low SWR on 80-10M, though noise levels and safety considerations warrant attention. This versatile design excels in constrained environments.

Guide to ground mounting antennas, notes on efficiency, elevated installations, metal towers and masts, other mounting schemas, moble homes and rv, lightning protections, artiche by Bencher

Open-Source Software Implementation of a DRM (Digital Radio Mondiale) Receiver. Dream runs on virtually any pc and requires a receiver front-end to work as a real radio.

This article compares two commercial vertical antennas for the 4-meter amateur radio band: the Watson WVB-70 half-wave and the Sirio CX4-71. The Watson measures 2.03m in length, costs around £40, and exhibited adequate performance but required additional waterproofing after rain affected its VSWR readings. The longer Sirio CX4-71 (3.02m) performed noticeably better, delivering signals approximately 2 S-points stronger than the Watson. The Sirio demonstrated high build quality, a stable 1.2-1.4:1 VSWR, and weather resilience, though minor VSWR fluctuations were observed during rain and frost. Both antennas are half-wave designs requiring no ground plane radials.

This resource details the four primary functions of a ground system: lightning energy dispersion, equipment safety, RF return path provision for end-fed antennas, and management of induced RF currents. It clarifies that a ground system's effectiveness varies depending on its specific function, noting that a good lightning ground might not be an effective RF ground. The content emphasizes that proper antenna system design, including baluns and appropriate feedline lengths, often negates the need for an RF station ground to mitigate common mode currents or RFI in the shack. The article quantifies lightning energy, stating its peak is in the dozens or hundreds of kilohertz, with damaging energy extending to hundreds of megahertz, and currents reaching thousands of amperes. It recommends solid, wide, smooth copper surfaces for ground leads to achieve low impedance across a wide frequency range. The author, W8JI, shares practical insights from his station, which includes two 300-ft towers and four 130-ft wire verticals, detailing his use of common point grounds and _DX Engineering RR-8 HD_ antenna switches for lightning protection without coaxial surge protectors. Specific examples of antenna systems prone to common mode current problems are listed, such as random wire antennas without proper feedline lengths and off-center fed dipoles. The text also explains how a ground screen or radial system can reduce local noise sensitivity for vertically polarized antennas by covering the lossy earth.

The Yaesu FT-1000MP Mark-V, introduced at Dayton 2000 Hamvention, features a higher RF power of **200 W PEP** and a Class-A amplification SSB mode at 75 W. Key enhancements include an _Interlocked Digital/Analog Bandwidth Tracking system (IDBT)_, a Variable Front-End Filter (VRF) preselector, and improved ergonomics, notably a multi-function shuttle jog dial. This model, a successor to the 1996 FT-1000 and FT-1000MP, was designed to compete with high-end transceivers, despite its retail price of $4200 initially. The transceiver's physical dimensions are 406 x 135 x 348 mm (16 x 5.3 x 13.7 inches) with a weight of 14 kg (31 lbs), making it substantial. Its rear panel offers over 20 connections, including power, external DSP speaker, BAND DATA I/O, ALC, and multiple interface jacks for DVS-2, Packet, and RTTY. The unit also provides two keyer inputs, a DB9M serial interface for CAT, and two PL female antenna connectors, plus additional receive antenna jacks. Despite its advanced internal architecture, including two independent receivers with their own IF filters and AGC loops, the display technology, utilizing fluorescent discharge rather than LCD, contributes to an older aesthetic. The control panel is extensive, featuring 92 knobs and buttons, alongside numerous LED indicators for various modes and functions.

Butternut article on radials usage on vertical and ground plane antennas

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.

Digital radio mondiale DRM products, measuring tools, Magnetic field probes, RF power meters, Broadband loop antennas, DRM devices and services

Pictures and description of a SteppIr vertical antenna setup in a small backyard using DX Engineering radial plates.

Nice feature of the Baofeng UV5R family is that they support 6.25kHz tuning steps. That fact makes it possible to dial in the radio to use the exact PMR446 channel frequencies rather than a nearest fit which is the case in many other transceivers.

Low Cost frequency counters and DDS VFO's for QRP and Vintage Radio's. LCD Digital Display, Frequency Counter or DDS VFO

Antenna modeling discussions about What happens if... a dipole is bent horizontally, laterally, vertically. Zig-zag, meander, catenary curve. Effect of sag, elevation, radials. OCF off-center feed, harmonics. Includes 4NEC2 antenna models for each study.

Radials & Counterpoise

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.

About DRM, the DRM standard, emission types, upfrading your old HF RX to DRM

The **TransWorld Antennas TW2010 Traveler HF Portable Vertical Antenna** assembly video provides a visual walkthrough for deploying this popular portable HF antenna. It details the step-by-step process, from unpacking components to final setup, which is crucial for operators preparing for field day operations or DXpeditions. The video focuses on practical aspects, showing how to connect the various elements and secure the antenna for optimal performance. Operators often seek clear assembly instructions for portable antennas like the TW2010 to ensure quick and correct deployment in diverse environments. This visual aid helps clarify potential ambiguities found in written manuals, illustrating the proper handling of the antenna's radial system and telescopic elements. The video serves as a valuable resource for those aiming to achieve efficient operation with the **TW2010 Traveler** in a portable setting. Understanding the assembly sequence can significantly reduce setup time and prevent common errors encountered during initial deployments.

The TransWorld Antennas TW4040 The Adventurer Monobander™ is a portable HF antenna designed for rapid deployment in field operations, including **SOTA** and **POTA** activations. This manual details the antenna's assembly, tuning procedures, and operational guidelines for optimal performance on the 40-meter band. It outlines the specific components, such as the telescoping whip and base unit, required for proper setup. Instructions cover mast erection, radial wire deployment, and impedance matching to achieve a low **VSWR** across the designated frequency segment. The document also provides guidance on antenna orientation and environmental considerations for portable use. It specifies the antenna's power handling capabilities and physical dimensions when fully deployed and collapsed for transport.

A multiband vertical antenna for HF bands with elevated ground radials slant down at 45 degrees and acting also as guy wires.

The Superantennas MP-1 portable HF antenna is analyzed for its design and field performance, particularly its high-Q loading coil and 3/8-inch mounting. The review details the antenna's construction, including an 8-inch vertical section, a large-diameter loading coil tuned by a sleeve, and a 4-foot whip that disassembles into six rods for transport. Initial testing with the supplied 10-foot ribbon cable "ground plane" yielded poor SWR and RF hot conditions, indicating an inadequate ground system. Further experimentation with longer radials and resonant counterpoises for each band improved matching and eliminated RF hot issues, but introduced significant operational complexity. The author notes the difficulty in optimizing both counterpoise length and coil setting without an antenna analyzer, and the sensitivity of the MP-1 to counterpoise deployment. The review also discusses the recommendation to tune for maximum received signals rather than minimum SWR, often necessitating an external ATU due to the antenna's typical low impedance. The **MP-1**'s critical dependence on resonant counterpoises for effective operation, especially when elevated, is highlighted as a major drawback for portable use. The author ultimately sold the antenna, concluding that despite its sound technical design, its fussy nature and the need for extensive counterpoise management or an ATU detract from its portability and convenience compared to simpler, less expensive dipole solutions. The **Superantennas MP-1** is deemed a flawed portable antenna, requiring considerable effort to achieve its claimed performance.

A simple drawing schematic of a portable field dipole for 14 MHz with dimensions in meters and instruction for setting up the antenna and to store the radial for easy transportation

A helically wound vertical antenna experiment. 14 meter of wire wounded on a 8 meter fishing pole with 4 elevated radials

A 102-inch vertical whip, commonly a CB antenna, forms the core of this low-profile 10-meter antenna design, optimized for the 28 MHz band. The construction details specify three 8-foot radials made from scrap wire, connected to a common point. This simple yet effective setup is designed for ease of construction and deployment, making it accessible for operators with limited space or materials. The design emphasizes using readily available components, including PVC pipe for the mast and a SO-239 connector for the feedline, ensuring a straightforward build process for a resonant quarter-wave vertical. Field results indicate that this antenna provides good performance for local and DX contacts on 10 meters, despite its compact footprint. The author, N8WRL, shares practical insights into its construction and tuning, highlighting its suitability for temporary or permanent installations where a full-sized antenna might be impractical. Comparisons to more complex designs suggest that this low-profile vertical offers a respectable signal-to-noise ratio and effective radiated power for its size, proving that simple designs can yield satisfying on-air results.

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.

K1JJ presents a compilation of insights regarding vertical radial ground systems, specifically applied to 160m vertical arrays. The resource details 19 distinct observations and recommendations, emphasizing that ground radials primarily reduce ground losses rather than influencing pattern formation. It explains that RF current flows inefficiently through average soil, necessitating copper radials to create a low-resistance path back to the antenna base. The content suggests that **50-60 radials** are generally sufficient to achieve optimal efficiency, with diminishing returns beyond that number, and that radials should be laid on the surface for best performance. The discussion also addresses practical aspects such as wire gauge, installation techniques using 'U' shaped staples, and methods for connecting radials in multi-element arrays. It highlights the importance of radial length, stating that 1/4 wave radials are a crucial minimum, and that for 160m, radials should be at least _100 feet_ long. The resource critically examines the efficacy of elevated radials versus ground radials, noting that while a few elevated radials may suffice for VHF, HF applications, particularly on 160m, require extensive ground radial systems to efficiently collect RF currents in the near field. It also touches on the impact of radial systems on parasitic elements and the significance of symmetrical radial patterns for minimizing losses. Further practical advice includes wire type recommendations, proper soldering and weatherproofing techniques for radial connections, and considerations for integrating steel towers into the ground system. The author shares personal experience with installing 60 quarter-wave and half-wave radials under each of three in-line verticals, expressing satisfaction with the results.

The Icom IC-7300 is a groundbreaking Software Defined Radio (SDR) transceiver that revolutionizes the way amateur radio operators interact with the spectrum. With its large 4.3-inch color TFT LCD touch screen, users can easily navigate through various functions, including real-time spectrum scope and high-resolution waterfall displays. This allows for quick adjustments and enhanced signal awareness, making it easier to find and engage in QSOs. The touch screen interface provides a modern approach to radio operation, replacing traditional buttons with virtual controls that can be accessed with a simple touch. In addition to its user-friendly interface, the IC-7300 boasts advanced features such as IF-DSP filtering, audio scope functions, and a multi-dial knob that combines tactile control with touch screen flexibility. These capabilities enable operators to visualize signals and make precise adjustments to their settings, ensuring optimal performance during contests or casual operating. The IC-7300 is designed for both beginners and experienced hams, making it a versatile addition to any shack. Its innovative design and functionality truly embody the spirit of modern amateur radio.

Bill Turner dialcover site, dial cover replacements for antique radio restoration

Decode DTMF from your iPhone. Hold your smartphone close to a DTMF source and this app will decode the numbers being dialled.

Cloth covered wire from sundial wire

An home made remote antenna tuner project that with a 6 meter random wire and two radials of about the same length, can tune from 40 to 10 meters without any issue.

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.

Effect of radials on the efficiency of antennas.

Constructing an End-Fed Half-Wave (EFHW) antenna offers a practical solution for HF operators seeking a multiband wire antenna without the need for extensive radial systems. This design typically employs a high-impedance transformer at the feed point, matching the antenna's inherent high impedance to a 50-ohm coaxial feedline. The article specifically details a 2012 approach, focusing on a transformer with a 49:1 turns ratio, which is a common configuration for EFHW antennas. The resource outlines the construction of a wire element cut for a half-wavelength on the lowest desired band, with specific coil arrangements enabling operation on harmonically related bands such as 40m, 20m, and 10m. It discusses the physical dimensions and winding details for the matching transformer, often utilizing a ferrite toroid core to achieve the necessary impedance transformation. The content provides insights into the operational principles and practical considerations for deploying such an antenna, including methods for tuning and optimizing performance across multiple amateur radio bands. While acknowledging that the presented information from 2012 may be superseded by newer insights, it serves as a foundational reference for understanding EFHW antenna theory and construction.

An experimento of a 40 meter delta loop antenna both in horizontal and vertical polarization and several elevation angles with interesting notes about the effect of the radial field under the antenna.

DIAL Radio Club is affiliated with the American Radio Relay League. The DIAL Radio Club has a membership of 110+ members from the southwest Ohio area.

The TBJ-1 – a triband base antenna was published in March 2017 QST. This antenna covers 2M/220 MHz/70cm in one 6ft 3/4 inch PVC pipe and requires no radials.

This article presents an innovative homebrew antenna design utilizing surplus ladder line as a receiving antenna for HF and MF bands. The Ladder Line Antenna (LLA) transforms standard 450-ohm ladder line into a directional, bidirectional, or omnidirectional antenna system through different termination methods. The design, which requires minimal space and height, achieves 6-10dB front-to-back ratio on 40-160m bands using a 33-foot length. This DIY wire antenna project offers an efficient, low-profile solution for amateur radio operators, featuring broadband operation without ground radials and easy installation below fence height.

The Baofeng UV-5R handheld transceiver, introduced around 2012, operates across the 2-meter (144-148 MHz) and 70-centimeter (420-450 MHz) amateur bands, offering dual-band receive and transmit capabilities. This review provides an early assessment of the radio's form factor, user interface, and general performance, noting its compact size and the inclusion of a **VFO/Memory mode** button for frequency management. The device supports both FM and narrow FM modes, with a reported power output of 4 watts on VHF and 3 watts on UHF, making it suitable for local simplex and repeater operations. Key features discussed include its 128-channel memory capacity, a built-in VOX function, and a **DTMF keypad** for tone dialing and repeater access. The review highlights the radio's ability to scan frequencies and memories, along with a dual-watch function allowing simultaneous monitoring of two frequencies. Battery life is addressed, with the standard 1800 mAh Li-ion pack providing several hours of operation depending on transmit usage. Initial impressions cover the radio's construction and the clarity of its LCD display, which shows both A and B band frequencies.

Efficient Low Band Counterpoise for Restricted Circumstances Loss Avoidance Opportunities and Techniques for the Low Bands The short and linear FCP was designed to reduce ground losses from inadequate radial systems beneath inverted L and other vertical antennas.

A quarter wave vertical omni-directional antenna for 7 MHz. Formulas for dimensions in feet and meters are provided. Ideal radial angle is between 35° and 45°. Velocity factor (Vf) varies based on coax type.

Clarifies the intricate process of calibrating the _Elecraft K2_ dial, addressing common user challenges and lively discussions on the Elecraft reflector. Wilhelm, W3FPR, dissects the K2's PLL synthesizer design, chosen for its low phase noise, kit-friendly duplication, and cost-effective components. The resource emphasizes the critical role of the 4000.000 kHz reference oscillator's accuracy during CAL PLL, CAL FIL, and CAL FCTR functions, noting its dependence on temperature and crystal stability for optimal performance. Explaining the K2's frequency display, the document reveals it relies on microprocessor-driven look-up tables generated by CAL PLL for VFO values and CAL FIL for BFO values. In SSB and RTTY, these combine, while CW and CWr modes also factor in the sidetone pitch. The author details inherent limitations, such as the 10 Hz increment resolution of the dial and varying PLL step sizes—from 3 Hz on 160 meters to 10 Hz on 10 meters. BFO increments range from 20 to 35 Hz, collectively limiting practical dial accuracy to within **20 Hz** with diligent effort, or **30 Hz** for a slightly less demanding task. The guide outlines a four-step calibration procedure: setting the reference oscillator, running CAL PLL, running CAL FIL, and setting all BFOs. It highlights the _N6KR Method_ as a particularly easy and accurate approach, requiring only the K2 and a known frequency source like WWV for zero-beating, eliminating the need for external test equipment.

In this post by N6CTA, discover the conversion of the Yaesu ATAS-120A screwdriver antenna for portable use. The author details the creation of two sets of radials, 16 and 32 in 16ft lengths, aiming to optimize the efficiency of ground-mounted antennas. Additionally, insights are shared on attaching male quick disconnect blade tabs, with potential plans for a radial plate kit.

A review of the GAP Challenger DX Antenna that is not a traditional 1/4 wave vertical, but is a vertical dipole, this gives it several advantages over a standard 1/4 wave vertical, mainly the reduced number of radials, with excellent performances.

Current Solar Wind Conditions

The PAC-12 Antenna, a multi-band portable vertical, is meticulously detailed in this construction article by James Bennett, _KA5DVS_. The design emphasizes ease of homebrewing using readily available components from local hardware stores, including replaceable loading coils. It outlines the preparation of the 72-inch telescoping whip (originally from Radio Shack, with an alternate source now provided by _Pacific Antenna_), the construction of the loading coils from PVC risers, and the fabrication of the aluminum rod base sections. Specific instructions cover threading aluminum rod with a _1/4-20 threading die_ and assembling the feedpoint insulator with a BNC connector, along with recommendations for radial deployment. KA5DVS, an avid traveler and QRP enthusiast, developed the PAC-12 to address the bulkiness of random wire setups and the limitations of commercial portable antennas like the Outbacker or SuperAntennas MP1. His goal was a lightweight, packable antenna that disassembles into 12-inch sections, achieving an assembled length of approximately 8 feet. The design strategically places the loading coil away from the base for improved efficiency. The PAC-12 notably placed first in efficiency compared to a quarter-wavelength wire vertical at the HFPack antenna shootout during the Pacificon conference in October 2001, demonstrating its practical performance for field operations. Appendix C showcases various _NJQRP Club_ members' PAC-12 constructions, including a 20m beam made with multiple PAC-12 elements.

This article describes a simple yet effective multi-band vertical HF antenna design that performs exceptionally well across 80m to 10m bands. The antenna consists of a 13.4m wire mounted on a 12.4m Spiderpole, complemented by four 12m radials and a ground rod. Initially tuned with a manual LC circuit, it was later upgraded with a CG3000 remote auto ATU for convenient band switching. Despite antenna modeling software suggesting limited performance on higher frequencies, the system demonstrated excellent DX capabilities across all bands, outperforming more complex vertical antenna designs.

The CWJF Group began in the 80's with the ideas of an excellent telegrafist, our dear friend Julio (PY4AG) who with customary cordiality taught those interested in practice of morse code.

This document details the construction of a multi-band end-fed antenna, suitable for situations with limited space for larger antennas. The design utilizes a 1:49 to 1:60 impedance transformer to match a half-wave wire antenna fed at one end. Compared to a traditional dipole, this antenna resembles a highly unbalanced Windom antenna with one very long leg and a virtual short leg. The design eliminates the need for radials but relies on the coax cable shield for grounding. The document recommends using at least 10 meters of coax and installing a common mode filter at the entry point to the shack for improved performance.