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The Contesters Choice

30/17/12 and 20/15/10-Meter Tribanders and a 40 meters inverted V wire yagi antenna

Put up the longest dipole you can fit, feed it with open wire line, connect it to the balanced output of your tuner and poof! Instant multiband antenna. Is life really that simple?

An interesting page about Quad antennas. Modelling QUAD antennas, comparing quad antennas to yagi antennas. Information on QUAD Antenna tuning and home brewing with help on calculating dimensions and tuning.

Some antenna manufacturers place baluns at the incorrect location in LPDA arrays, or tell you to route the cable incorrectly. This can cause substantial RFI and all sorts of weird problems like RF into house wiring.

This note describes a relatively small, but efficient, loop antenna initially created for portable operation. With suitable modifications, it can be adapted for fixed station use. In this age of CC&Rs, an antenna similar to this may very well be the answer to your problems. Have a look, be inspired, get out the torch / soldering iron and create your own version!

Moxons work great, and they take up less space than full size two element Yagis

Local and DX contacts from tight spaces, it works from 40 to 17 meters

A popular 2 meter antenna returns in an improved, easier to reproduce form, 2008 QST article

A different approach can help you optimize attic-bound aerial by W6HPH

This note looks at the antenna and antenna model for the 40 meter Moxon Yagi designed by Dave Leeson, W6NL. The performance of the antenna, through the model, will be explored in several typical settings.

A folded wire antenna for 160 meters as appeared on 73 amateur radio magazine june 1997

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

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

A project for a homemade multiband Hexbeam antenna for 10, 12, 15, 17 and 20 meters

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.

F5DQK repairing and swr measurement tests of a Cushcraft R7 Antenna

This page will help you answer important questions about antenna selection before you talk to a supplier. After reading this paper, you should be able to better determine the most important parameters you need to know for your antenna selection criteria.

A Half wave antenna has a high impedance feed point. This can be matched using a 1/4 wave stub matching section and converts the 40m vertical into an L-shaped 20m J-Pole antenna. The 300 ohm feeder used for this purpose must be kept away from the ground.

Original article published on February 1992 on 73 Amateur Radio Today about the 2m and 70 cm copper cactus J-pole antenna

Antan is a homemade antenna analyzer project by F6BQU

A dipole for 2m, 4m, 6m band an hamdwritten note for a homemade vhf antenna that can be tuned across the VHF band

German antenna manufacturer for VHF UHF antennas, Quad-antennas, yagi-Antenna, LPDA-Antenna, W-Lan Antennas.

Cheap Antennas for the AMSAT LEO Kent Britain WA5VJB

A helpful guide to building your own beverage-type low noise receiving antenna for broadband use. Easy, do-it-yourself suggestions to optimize directional performance, even if you lack a farm to put it on.

Some antenna manufacturers place baluns at the incorrect location in LPDA arrays. If we consider what the balun does we can see how the mistake occurs.

The document provides a comprehensive overview of baluns, which are devices used to connect balanced loads, like dipole antennas, to unbalanced inputs, such as coaxial cables. It covers various types of baluns, including voltage and current baluns, and their design, construction, and testing. The text discusses the importance of baluns in preventing RF currents on coax shields and their applications in Ham radio setups. It also includes practical advice on selecting and using baluns based on antenna impedance and power ratings, along with detailed performance evaluations and construction tips for different balun configurations.

If you have space constraint at your QTH for a HF antenna, you can try contructing this HF magnetic loop antenna for 40-20 meters bands

A 21 MHz Four Square Beam Antenna This popular antenna for the lower bands, can also work well on 15 meters, QST Article

An end fed 20 meter half wave antenna

A scanned PDF of this interesting book on HF Dipole antennas published by Stanford Research Institute

The _National Contest Journal_ (NCJ) serves as a dedicated resource for amateur radio contesters, providing in-depth articles, operational strategies, and technical insights. Published bimonthly by the ARRL, it covers a wide array of contesting topics, including antenna systems, station optimization, operating techniques, and rule interpretations for major events like the NA Sprint and various QSO Parties. The journal aims to enhance the competitive edge of participants across all skill levels, from casual operators to serious multi-operator teams, by sharing experiences and data from high-scoring stations. NCJ content frequently includes detailed analyses of contest results, offering breakdowns of scores, participant statistics, and comparisons of operating strategies. Readers can find practical advice on improving their contest performance, such as optimizing logging software usage or maximizing **run rates**. The journal also features columns on specific contest modes like RTTY and provides updates on rule changes and upcoming events, helping contesters prepare for future competitions and achieve better results, often leading to **top 10** finishes in their respective categories.

An excellently presented article on the design and construction of a medium wave DX Antenna

All antennas that are situated close to the ground are affected by that ground to some extent. This article explain effects and benefits of counterpoise.

A complete guide to magnetic loop antenna construction, with analysis of multi-turn and single-turn magneti loops, and and insight on choosing the optimal capacitor, or homebrewing your own butterfly capacitor

Memorandum on the Beverage Wave Antenna for Reception of Frequencies in the 550 - 1500 Kilocycle Band", FCC Report 9.2.1, by Benjamin Wolf and Adolph Andersen

Presents a QRP AM/CW transmitter project specifically designed for the 10-meter band, utilizing a crystal oscillator and a collector-modulated AM oscillator. The design employs a 2N2219(A) transistor in a Colpitts configuration, generating 100 to 350 mW of RF output power depending on the 9-18 Volt supply voltage and modulation depth. Frequency stability is maintained by a 28 MHz crystal, with fine-tuning possible via a Ct1 trimmer capacitor for approximately 1 kHz adjustment. The resource details the RF oscillator stage, implemented with a 2N2219 NPN transistor, emphasizing frequency stability and low power dissipation. It also covers the amplitude modulation stage, managed by a 2N2905 PNP transistor, which impresses audio information onto the carrier. Selective components (C3, C4, C7, C5) enhance voice frequencies within a +/- 5 kHz bandwidth, and modulation depth is controlled by R2 and R3. The project includes a 3-element L-type narrow bandpass filter (Ct3, L3, C10) to suppress harmonics and ensure a clean output signal. The project provides a complete schematic diagram, a comprehensive parts list including specific capacitor, resistor, and inductor values, and construction notes for the coils (L1, L2, L3). It also offers practical advice on enclosure requirements, suggesting an all-metal case or a PVC box with graphite paint for RF shielding. Operational parameters such as current draw (27mA@9V to 45mA@16V) and input impedance (50 Ohms) are specified, alongside guidance on antenna matching and the importance of a valid amateur radio license for 10-meter band operation.

The skeleton slot antenna design was developed in the UK for TV use soon after WW2. This document describe and adapted version for the 2 meter band

A two meter Quad antenna project with detailed instructions on how to adjust the Quad gamma match

An Experimental, High-efficiency, Graphic-Tunable Magnetic Loop antenna and loop controller in a 52 pages PDF presentation with drawings and pictures

The design and feeding of driven elements for VHF/UHF Yagi antennas , modeling, observations and some case studies by Graham Daubney F/G8MBI

Presentation by AC8GY on classic G5RV Antennas and other horizontal dipoles, the popular G5RV, ZS6BKW, dipole fan, Alpha-Delta DX-CC and a trap dipole are modeled in EZNEC and compared.

Ever need a way to estimate the amount of wire to add to or remove from a center-fed wire dipole antenna to achieve resonance at a desired frequency? This article help to determine correct wire lenght.

In this PDF article Zack Lau describe how to homebrew a four element yagi beam antenna for 50 MHz band, including how to build mounting blocks and tubing clamps to hold elements.

Mounting on Roof or at Ground Level? Why ground plane antenna works better at lower level.

A trap on the coaxial cable, also known as choke, helps to eliminate the sneaking of the reflected RF- energy to the shack. The trap can be made from the coaxial cable that feeds the antenna

This QST article describes the electrical and mechanical design process for two LPs that cover the HF bands from 10-30 MHz

Dealer for Alpha Delta hf antennas, switeches, Outbacker and super antennas, morse code keys, coax cable and military products, managed by W8GEG from Medina Ohio

A system designed to automatically tune small transmitting magnetic loop antennas, particularly beneficial for **contest operations** where rapid frequency changes are common. The core of the system involves a PC-based control application, AutoCap, written in C#, which monitors antenna SWR via an external meter and commands a motor interface to adjust the loop's variable capacitor. The software is compatible with Windows and Linux via the Mono framework, offering a graphical user interface for monitoring system status, SWR, power, and motor commands. Key components include one or more magnetic loop antennas equipped with DC or stepper motors for capacitor adjustment, an SWR meter with data output (such as the Telepost LP-100A or a homebrew serial/USB SWR meter), the AutoCap PC software, and a motor interface. The most effective motor interface utilizes an **Arduino-based controller** with custom firmware, providing precise control over both simple DC motors and stepper motors, and supporting features like motor braking for finer adjustments. The system allows for configurable SWR thresholds, pulse widths, and motor effort settings to optimize tuning speed and resolution. Optional radio integration provides frequency hints, enabling the algorithm to learn the relationship between motor actions and resonant frequency, thereby speeding up initial tuning responses. The software also supports antenna profiles, allowing operators to save and recall specific configurations for different loops, including accumulated frequency hint data.

Types of coax-cable with rf attenuator calculator, line loss calculator form includes an antenna gain calculator. This coax loss calculator can help you on choosing the right cable for your antenna sysmte.