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96 links - and 1 categories

A Low Profile 10 Meter Antenna - A simple vertical whip antenna for 28 MHz with three radials made of 8 foot pieces of scrap wire and a 102 inch whip
[ Hits: 469 | Votes: 2 | Rating: 9.5 ]

K6MM 160m Antenna Modifications - After a storm damaged the antenna, W6AER replaced it with a pre-made capacitance hat from DX Engineering. Using hose clamps and conductive grease, he ensured durability. Experimenting with radials and a coil, he aimed for better performance and resilience.
[ Hits: 46 | Votes: 0 | Rating: 0 ]

Building a 40m Delta Loop Antenna - 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.
[ Hits: 291 | Votes: 4 | Rating: 8.25 ]

A very efficient half size 40 meter Vertical Antenna - 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.
[ Hits: 736 | Votes: 4 | Rating: 8.5 ]
Vertical bazooka antenna for the 40m - 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.
[ Hits: 135 | Votes: 7 | Rating: 6.85 ]

Half-Size 6 meter J-antenna - How to use a little known J-antenna characteristic to reduce a conventional 14 foot antenna to 7 feet. Perfect 50 Ohm match, same gain, no radials.
[ Hits: 63 | Votes: 0 | Rating: 0 ]

Multi-Band End-Fed Antenna Design for Limited Space ^new - 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.
[ Hits: 76 | Votes: 0 | Rating: 0 ]

Notes on Designing LF-MF antennas - A free book on designign LF MF antennas. The six chapters in the body of the book are limited to basic information which, combined with a little modeling or simple calculations, can be applied directly using graphs for special problems like inductor design.
[ Hits: 267 | Votes: 2 | Rating: 9.5 ]

ZR6KMD 20m Field Dipole - 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
[ Hits: 517 | Votes: 3 | Rating: 7.33 ]
Yaesu ATAS-120A Portable Tripod: Enhancing Efficiency - 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.
[ Hits: 86 | Votes: 0 | Rating: 0 ]

Optimizing Ground Radials in End-Fed Antennas - An interesting article focused on defining the optimal lenght and number of ground radials in vertical, inverted-L, end-fed antennas. This article compares also the radial length vs number of ground radials to power loss in transmitted power.
[ Hits: 433 | Votes: 1 | Rating: 10 ]

Tri-Band VHF/UHF Antenna Design - 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.
[ Hits: 213 | Votes: 0 | Rating: 0 ]

Modified Ground Plane Antenna Adds Second Band - This article explains the trick of how to shorten and lengthen pairs of radials to make a 2-band ground plane antenna. Included is a "Table of Multi-Band Possibilities" covering the range of 6 to 40 meters.
[ Hits: 53 | Votes: 0 | Rating: 0 ]

Field Day Inverted L - Inverted L antenna, even if not completely freestanding, it only requires one line to be lauched into a tree to support the end of the horizontal wire. This project is done with a 31-foot Jackite pole for a support and uses six 15-foot radials and one 33-foot radial.
[ Hits: 88 | Votes: 0 | Rating: 0 ]

Hamstick Experimentation: A Day of Surprising Results - In his POTA activation, WK4DS experimented with radials for hamstick antennas. Despite sun and RF noise challenges, successful connections were made. Surprisingly, tuned radials proved unnecessary, simplifying setup. Hamsticks demonstrated versatility across frequencies. Increased power improved signal quality, sparking his curiosity for further exploration in radio technology.
[ Hits: 44 | Votes: 0 | Rating: 0 ]

Challenger DX Antenna Review by NK7Z - 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.
[ Hits: 221 | Votes: 2 | Rating: 10 ]