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Pipe your signals to 146 and 445 MHz with one antenna!

5 elements Yagi antenna with an 8.7 db gain

You can make your own 2-meter "rubber duckies" that will likely perform much better than many commercial units.

Optimising a typical G5RV antenna by VK1OD

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

Adventures in amplified GPS antenna construction; an experiment

Why twinlead isn't necessarily a low loss feed line.

A well documented article about construction and analysis of a horizontally polarized halo antenna for 6 meters band by Dr. Carol F. Milazzo, KP4MD

Shortened vertical antenna for 40 meters band an homebrew project

6m (50Mhz) Long wire antenna There is another form of long wire antenna which provides uni-directional coverage and is easy to build. Description by Arnie Coro CO2KK

This is a design for a stealthy HF multi-band vertical wire antenna using a tree as a supportby G7AQK

Cheap UHF antenna plans for 2 meters and up including 421 1296 and 902 Mhz

A flex antenna working on 6m and 70cm by K0EMT

A trapped dipole antenna based on the orignal W3DZZ antenna design resonating on 80 40 20 15 10 meters

A bowtie antenna is a type of antenna that reputedly provides higher gain at lower radiation angles than a center-fed dipole antenna at heights considerably less than 1/2 wavelength above ground.

The G5RV multiband HF antenna, designed by Louis Varney (G5RV) in 1946, is a popular compromise antenna offering good overall performance on most HF bands when paired with an external antenna tuner. The basic full-size G5RV measures 102 feet across the top for 80 through 10 meter operation and is fed at the center via a 34-foot low-loss feed-stub. This interaction between the radiating section and the feed-stub facilitates matching across 80-10 meters with a standard tuner, often eliminating the need for ladder line directly to the shack. The antenna's design center frequency is 14.150 MHz, configured as a 3/2-wave dipole on 20 meters, with its 102-foot length derived from long-wire antenna formulas. Construction details emphasize the matching section, which can be open wire, ladder line (window-type), or TV twin lead. Each type has a specific velocity factor (VF) affecting its physical length for an electrical half-wave on 14 MHz; for instance, open wire requires 33.7 feet (VF 0.97), ladder line 31.3 feet (VF 0.90), and TV twin lead 28.5 feet (VF 0.82). The article provides formulas for calculating these lengths and discusses the antenna's behavior on individual bands, from 3.5 MHz where it acts as a shortened dipole, to 28 MHz where it functions as two three-half-wave long-wire antennas fed in-phase. Practical construction notes include recommendations for vertical descent of the matching section, sealing the coax junction, providing strain relief, and winding a coaxial choke coil to mitigate common mode current. The resource also presents dimensions for double-size (204 ft) and half-size (51 ft) G5RV versions, along with their corresponding matching section lengths for various line types, making it a versatile reference for hams considering this classic wire antenna.

This article describes the antenna for Low Frequency Beacon. It originally appeared in the "Lowdown" for Oct. 1999.

This document contains the detailed instructions to build a homemade lindenblad antenna using a twin-lead as dipole elements. This document contains 9 pages and includes a detailed construction sequence and some drawings to build this antenna for UHF and VHF ham radio bands

Article on a 2 and 6 meters halo antennas that does not require a mast has a very low part count and can easily be built with a minimum of tools.

A 50-ohm 10W resistor forms the core of this portable QRP antenna, designed by _K0EMT_ for convenient operation on 160m and 80m. The construction involves soldering the resistor to a BNC connector, with one lead to ground and the other to the center conductor, then insulating the assembly. This minimalist design aims to provide a highly portable solution for low-band QRP operations, acknowledging the inherent trade-offs between antenna size and efficiency. Testing with an antenna analyzer revealed low SWR on both 160m and 80m, with a Yaesu FT-817 confirming good matching. While 40m and 30m showed higher SWR, the primary focus remains on the lower bands. The author successfully tested the antenna with **2.5W CW** output, demonstrating its practical application for QRP field operations where ease of deployment is paramount, even if it means sacrificing some **gain** compared to full-sized antennas.

The resource presents a mobile antenna mast mount designed for rapid deployment from a vehicle's trailer hitch, addressing specific design criteria for portability and ease of use. It outlines seven key design goals, including fitting inside a vehicle, handling various mast diameters, and enabling one-person setup without tools. The construction utilizes offset T-handled stainless bolts for tool-free mast securing and a "tab" mechanism to prevent collar slippage. Detailed deployment instructions are provided, covering steps from attaching the bottom collar to securing the mount in the hitch, erecting the mast, and tightening both collars. The author, K0EMT, reflects on potential improvements, such as welding the bottom collar for enhanced stability versus transportability. The project also credits AA0ZC for the physical construction.

Although a magnetic loop antenna(aka small loop antenna) is very compact, its efficiency is close to a half-wavelength dipole if carefully built.

A Low -Power Indoor Portable HF Antenna by Monty Northrup, by N5ESE

This article explores the Cobra Junior linear loaded antenna for 80m to 10m bands. This antenna is a linear loaded dipole described by W4JOH in 73 magazine June 1997

Mobile antenna placement presents unique challenges for the amateur radio operator, often requiring compromises between RF performance and mechanical considerations. This resource from KV5R.COM offers practical insights into achieving effective installations, drawing on real-world experience with different vehicle types. It details how factors like ground plane availability, proximity to vehicle structures, and antenna type (e.g., **HF mobile**, **VHF/UHF mobile**) influence signal radiation patterns and overall system efficiency. The author discusses common scenarios, from sedans and SUVs to trucks and RVs, highlighting the impact of mounting locations such as the trunk lip, fender, or roof. Specific attention is given to minimizing RF interference and maximizing radiated power, crucial for reliable mobile communications. Understanding the interaction between the antenna and the vehicle's metallic body is key to a successful mobile setup, and this content provides a solid foundation for making informed decisions.

Drawing and plan for an HF magnetic loop antenna

3d parts printed to build an EZ-Lindenblad 2 Meters LEO Sat antenna as designed from Anthony Monteiro

HB9MTN Capacitive antennas for 40m, 30m AND 20m

A SQ Loop antenna for 50 MHz, project include pictures and schematic diagram

4 elements Yagi antenna for 28 MHz

The 5/8 vertical it quite popular and matching solutions can vary

A New Twist on Portable Multiband HF Dipoles, a Multi-band Spiral Dipole Off-Center-Feed match (OCF) antenna solution.

A simple center-fed dipole made just with a thin-wall PVC pipe, aluminum tape, and RG-8X coax

A vertical monoband antenna design that can work from 6 meters to 70 cm by F5ZV in French

A simple VHF vertical aerial for the home station

A folded dipole using twin lead By W8HDU

This article explain how to homebrew and use an HF antenna analyzer by simply adapting a Windows PC, micro-controller and a DDS evaluation board by K6BEZ

A VHF UHF 5+5 elements yagi antenna by CE4WJK

Alford slot antenna for 1.3 GHz to 2.3 GHz.

Building a 2 metre 144MHz VHF Yagi beam antenna, designed for portable use.

A project of a bobtail-curtain antenna for 10 MHz

The GW3YDX Super Moxon antenna design improves upon the standard Moxon Rectangle by incorporating additional directors in a rectangular configuration, yielding enhanced directivity and gain. For the 6m version, modeling with 4NEC2 and EZNEC+ indicated a 3dB gain increase and a 26.5dB front-to-back ratio, with VSWR below 1.5:1 between 50.0 and 50.3MHz when optimized for 50.1MHz. This design achieves a narrower -3dB power point beamwidth of 60° compared to the original Moxon's 80°, contributing to better QRM rejection. The boom length for the enhanced design is just under 2m, approximately double the original Moxon's, with no increase in wingspan. Construction details include tubing lengths for 6m, 4m, and 2m versions, with specific dimensions provided for elements A through M, measured to tubing centers. For instance, the 6m version uses a 2160mm element A and a 2140mm element H. The design maintains a 50-ohm feed impedance, with practical models showing VSWR plots consistent with simulations after minor adjustments to driven element lengths. The article also references Moxgen software for initial Moxon parameter calculation and NEC/EZNEC model generation. The 2m Super Moxon version measures approximately 30" x 25", demonstrating the compact nature of the design across different VHF bands. The article highlights the antenna's performance in real-world DX contacts on 6m, achieving contacts with over 80 stations in the USA from a modest QTH.

Loop antenna picture gallery

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

DIY a Wi-FI Helical Antenna for better performances, a project by PA0HOO i Dutch end English

An HF multiband trapped antenna in french

EWE Antenna plan with a 9:1 balun

Accurately determining an antenna's feedpoint impedance is crucial for optimal performance, especially when experimenting with new designs or making adjustments. While SWR meters provide basic information, a full complex impedance measurement reveals the resistive and reactive components, which are essential for proper matching. Modern antenna analyzers, like the _Palstar ZM30_ or MFJ259B, simplify this task, but measurements taken through a transmission line require careful interpretation due to impedance transformation. This resource details a calibration method to precisely account for the effects of the feedline. It explains how a transmission line can significantly alter the measured impedance, illustrating this phenomenon with a Smith Chart example where an 80m antenna's [22 + j6] Ohms feedpoint impedance transforms to [82 + j45] Ohms after a 10m line. The guide demonstrates using a transmission line calculator applet, such as the one by W9CF, to reverse this transformation. It outlines the process of calibrating a specific length of RG174 coax, showing how an initial 26ft estimate was refined to **25.85ft** to accurately predict a known 22 Ohm load, significantly improving accuracy over uncalibrated results.

Antenna experiment a Delta loop antenna for 7 Mhz band

Extension to an existing fan dipole originally modeled for 40 20 and 6 meters. This modification will add 80 15 and 10 meter bands.