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A wip antenna for 6 meters band by JA1HWO

CB Radio, and 10 meters antennas manufacturer

An invisible magnetic loop antenna mounted under a table by PY1AHD

Build your own multi-band mobile ham antenna with a Hamstick

A QRP 900 grams hydraulic tuned small magnetic loop antenna by PY1AHD Alex.

Presents a detailed construction guide for a **Quadrifilar Helix Antenna** (QHA) optimized for 137 MHz, specifically for receiving weather satellite transmissions. The resource outlines the author's experience building previous QHA designs, highlighting challenges with tuning and nulls, and then focuses on a refined design by John Boyer, documented by Steve Blackmore, which proved easier to build and yielded superior reception. The guide provides precise element dimensions, including 1.5m of 32mm PVC pipe for the mast and 8mm soft copper tubing for the helix elements. It specifies lengths for horizontal tubes (190mm, 90mm) and helix elements (903mm, 1002mm), along with instructions for drilling, assembly, and forming a **balun** by wrapping RG58 coax around the mast. The text emphasizes critical steps like ensuring elements are square and twisting in the correct direction to avoid phase issues. It includes references to original QST articles by Buck Ruperto (W3KH) and the WxSat program for decoding satellite transmissions, contextualizing the antenna's purpose. The article concludes with a sample NOAA 12 image from September 1998, demonstrating the antenna's reception capabilities.

A magnetic loop made just of wire. Suitable for portable usage and for QRP operations.

An efficient 2 meter antenna disguised as a TV Satellite dish. This vertically polarized horizontal slot antenna, cut into the reflector of a TV dish, might be the ultimate stealth antenna.

W1YW QRZ page dedicated to fractal antennas

Calculate Cable Loss from SWR and reverse. Text file with only two simply formulas

Gamma match antenna is an antenna 1/2 additional lambda with the impedance matching more flexible arrangements (var capacitor) by sliding through the gamma match/road.

Article on radiation patterns of small loops, equivalent circuits of loop antenna, small loops as receiving antennas, ferrite loops

This project is an attempt to build a portable standalone VNA (Vector Network Analyzer).

All bands HF mobile antennas manufacturer

This resource details the conversion of an 80m elevated vertical antenna to include 160m operation, focusing on a relay-switched design over a trap-based approach. It presents specific feedpoint impedance values, such as **32 ohms** for 80m and **14 ohms** for 160m, and discusses the challenges of SWR drift encountered with the prior trap system during RTTY contesting. The article thoroughly explains the design choices for elevated radials, referencing _N6LF QEX data_ to debunk common myths regarding radial length and height, demonstrating that non-resonant radials can offer superior current uniformity. The construction section provides practical insights into building the vertical, including guying strategies, material selection from scrap pipe, and weatherproofing the relay assembly. It highlights the use of a common mode choke for the relay switching line, measuring approximately 5K ohms on both 160m and 80m, and details the L/C matching network's role in achieving a 50-ohm match at the end of a 300-foot RG-11 run. The author describes a precise VNA-based radial trimming procedure, achieving resonant values within a 3 KHz range. The content emphasizes the practical application of theoretical antenna principles, particularly concerning the interaction between the vertical element, cap hats, and the matching network. It offers a candid assessment of component selection, such as using junkbox parts and acknowledging the need for future upgrades to static drain resistors. The article serves as a comprehensive case study for advanced antenna builders tackling multi-band vertical designs.

Developed by Japanese 6 Meter Hams in the 1970's can be designed and built for almost any band

Demonstrates the design and construction of a 9-element Yagi antenna for the **70 cm band** (432 MHz), based on the DK7ZB concept. The resource details EZNEC+ calculations for a single antenna, providing gain, sidelobe suppression, and front-to-back ratio figures. It also presents a comprehensive analysis of stacking two such antennas, including optimal stacking distance (1000 mm) and the resulting performance enhancements for the stacked array, such as an increased gain of 17.03 dBi. The article includes detailed drawings, wire file dimensions in millimeters, and azimuth/elevation plots for both single and stacked configurations. Practical construction steps are documented with original photographs, illustrating element mounting, the **28 Ohm matching system** using two quarter-wave 75 Ohm transmission lines, and the critical N-connector wiring. It also covers the iterative process of fine-tuning the driven element length to achieve a return loss of 20 dB, validating the EZNEC+ simulation results with actual measurements.

Remotely controlled antenna switch that can switch between 5 antennas

Antenna accessories and related products

435 MHz double quad antenna by F5WN

Excel spreadsheet that help calculating dimensions of a high efficiency magnetic loop antenna for HF bands. Giving in input the loop perimeter, loop diameter and loop conductor will calculate electric characteristics, bandwidth, and efficiency

Choosing the right antenna for you, by Lewis G. McCoy W1ICP

Here is a way to ease assembly and balancing of a large antenna. The elements and boom are assembled separately in most cases. Once they are all together set up 2 tripods in the assembly area and put the boom on them.

A Low -Power, Distributed Capacitance Twisted Loop , indoor portable HF antenna by Monty Northrup, N5ESE

An 85ft wire fed against a 17ft counterpoise that works well in 80 and 40 meters

Simple, easy to build, low cost, compact, multiband By Robert Wilson, AL7KK

This magnetic loop is 78cm diameter, with the smaller Hertz loop for tuning. Feeding is by gamma match.

This group has been created to promote discussion relating to the EH Antenna. There should be many with experience with the EH Antenna, so don't be shy about asking questions on construction and efficiency.

A 2,4 GHz 13cm band quadrible qiad antenna with reflector offering a 14dbd gain

A Bulgarian bazooka antenna project by LZ2ZK

Antenne Cadre Project by F5NGZ, description by F5TZA in french

Very compact and high efficiency antenna ,very low radiation angle even at low height.

W3EDP multiband wire antenna, an extensive study and analysis of this antenna by W0ESE

A simple quarter-wave length vertical for 40m band using a 12 m spiderpole

This receive only loop covers a frequency range of about 5 MHz to 22 MHz and is built from readily available parts.

Plans and drawings of common amateur radio antennas, like jpoles, copper cactus, super jpole, omnidirectionals and quads

This article describes a loop usable from 7 - 21 mHz, using half inch copper tube 3 feet in circumference

Anyone attempting to work DX on Top-Band 160 Meters, soon learns of the need for a good receiving antenna. This is a 160 meter 8 element receiving array.

HX-B5i five band HexBeam installation

Comparison of several UHF antennas by DF9CY

A 67 feet long dipole doublet antenna

The antenna is a vertical dipole, around which four parasitic elements are forming a circle.

Homebrew antenna insulators for DK7ZB yagi antennas

An old project by I1VCF for a 3 element yagi antenna originally designed for 10/15/20 and extended to 24 and 18 Mhz in Italian

This project produces an inexpensive, multiband, end fed HF antenna matchbox, quick and easy to setup. This project creates a trifilar wound, 9:1 UNUN toroid matching transformer. Handles 100W and need an antenna tuner.

Progress in Design of Extremely Short Transmitting Antennas Short and still efficient, how is that possible? By Juergen Schaefer, DL7PE author of the MicroVert antenna concept. The MicroVert introduced in this document is an extremely short and hardly visible short-wave antenna with outstanding radiation properties

FDLog, a Python-based freeware application, addresses the challenge of synchronized logging for multi-station Field Day operations. It facilitates real-time data sharing across a wireless network, enabling operators to monitor band status and active transmitters at a glance. The software's input system is optimized for minimal keystrokes, streamlining the logging process during intense contest periods. Key features include database synchronization over a wireless network, ensuring all connected computers maintain identical log data. FDLog also incorporates a time synchronization function, designed to keep client programs within a second of a designated master machine, mitigating issues previously encountered with NTP. This internal clock sync can be optionally disabled if not required by the operating setup. Developed initially on Windows 2000, FDLog has demonstrated compatibility with _Linux_ and _macOS_ environments, though some font rendering issues may occur on the latter. The program assists in preparing the ARRL Field Day entry form, simplifying the submission of contest results. User feedback and ARRL rule changes drive ongoing development, with a discussion list available for community support and input.

Rhombic antenna definition and articles by answers.com

Slot antennas explained

One specific challenge in the KazShack, operating Single Operator Two Radios (SO2R), involved sharing a K9AY receive antenna between two transceivers without direct RF connection or manual feedline swapping. The solution, detailed in this project, adapts the **W3LPL RX bandpass filter** design to split 160m and 80m signals, feeding them to separate radio inputs while maintaining isolation. This approach also addresses the issue of strong broadcast band interference from a nearby 50KW WPTF transmitter on 680kc. The construction utilizes T-50-3 toroids and NP0 ceramic capacitors, built in a "dead bug" style on copper clad board. Each band's filter coils are identical and resonated to the desired frequency using an MFJ-259 antenna analyzer. A single DPDT relay, controlled by a remote toggle switch mounted on an aluminum panel, facilitates quick band switching between radios, simplifying low-band operations. While some signal loss is noted, the expected lower noise levels from the receive antenna are anticipated to compensate, potentially reducing the need for constant volume adjustments during toggling between transmit and receive antennas.