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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.

A project of a semi vertical trap antenna that can be tuned for 7 bands

The SARK100 Antenna Analyzer it is yet another antenna analyzer but available in kit form and designed to be easy to assemble and with an affordable pricing.

This site provides dates and rules of nearly 400 Amateur Radio HF contests. Based on google calendar system, offer the possibilty to integrate calendar events in your google calendar too.

50 MHZ Moxon antenna based on the KG4JJH design with some slight modifications in the construction

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

Demonstrates the design and construction of a compact, portable multi-band mini-delta loop antenna, specifically optimized for /P (portable) operations from remote locations like Scottish islands. The resource covers the theoretical underpinnings of half-wave loops, contrasting closed and open configurations, and then details the application of a folded dipole principle to achieve a 50-ohm match for direct coax feed. It presents empirical formulas for calculating element lengths, considering the velocity factor of common wire types, and provides a detailed example for a 20m (14.175 MHz) version. The article includes a comprehensive table of dimensions and allowances for a five-band (20m, 17m, 15m, 12m, 10m) mini-delta beam, along with construction hints for the central support and balun. It specifies a 1:1 trifilar balun wound on a ferrite rod and describes the antenna adjustment process using an _MFJ-259B Antenna Analyser_. Initial test results indicate an SWR of 1:1 at resonance and a bandwidth of approximately 240 kHz on 20m, even at a low height of five feet above ground. The distinctive utility lies in its focus on a practical, easily deployable beam antenna for portable DXing, offering a viable alternative to more complex or larger arrays.

A PDF File to download and print, with a table of all menu options with values, default settings, description and a quick reference guide of the front panel menus

The Kenwood TS-950S and TS-950SD HF transceivers are fine radios. However, many, if not all, of them were produced with a design flaw which allows the RG GAIN control to cease function in the presence of a strong signal IF the AGC has been turned OFF

How to Increase your CW speed article by George Allison, K1IG as published on QST

The Vee Beam antenna project presents a versatile solution for hams, enabling operation across all eight High Frequency bands (80m to 10m) with significant gain on 20m to 10m. This easy-to-construct antenna utilizes two long wires at an angle, enhancing directional performance and minimizing ground losses. With a low visual profile, it is discreet and effective for various applications. The design allows for optimal leg lengths and included angles, ensuring robust performance while maintaining simplicity in construction and operation. The V Beam antenna is an aerial that you can use on all eight High Frequency amateur bands (80, 40, 30, 20, 17, 15, 12 and 10m) with an antenna tuner, and which gives significant gain on the five bands from 20 to 10 meters band.

This article presents a technical investigation into spurious emissions from the Yaesu FT-847 transceiver when operating on the 70MHz (4-meter) band. The author discovered significant problems with both factory "UK spec" and modified units. Spectrum analysis revealed that when transmitting at 70.2MHz, the radio produces numerous spurious signals, with the most prominent emission at 45.6MHz measuring only 3dB below the fundamental frequency. The study also documents poor power efficiency on 4m (10.3% at 30W output) compared to 6m operation (23.5% at 30W). Tests verified that jumper configurations had no effect on filter selection. The author warns that using these radios on 4m may violate license conditions due to excessive spurious emissions.

Step by step instructions for setting up N1MM Logger to communicate with the TS-590S using the USB connection

A 3 element yagi antenna project for the 144 MHz band by PY5ALZ in portuguese

A simple antenna tuner for 4m by Tony Hawker G4CJZ

A small antenna for limited space / lanai use.

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

This program demodulates the telemetry data signal transmitted by the AO-40 satellite (aka Phase III-D) using the PC sound card

A means of sync-ing your computer clock using a GPS Receiver. GPS2Time is another GPS network time synchronization software application for Window 7 and higher. Freeware.

Making your own 2 metre (146 MHz) 5/8th wave whip antenna

A 500-watt mobile antenna project details the conversion of an old 10m hamstick into a highly efficient, multiband "bugstick" for HF operation. The core modification involves replacing the original coil with 25 turns of 6 turns-per-inch, 1.5-inch diameter coil stock, fabricated from #14 wire. This design, intended for a 3-magnet mount on a vehicle cab, achieves resonance on multiple bands by shorting out specific turns on the coil, similar to a **bugcatcher** antenna. Measurements taken with an MFJ-259 analyzer on a GMC pickup show 0 turns shorted for 20 meters (14.2 MHz), 10 turns for 17 meters, 16 turns for 15 meters, 19 turns for 12 meters, and 23 turns for 10 meters. The construction emphasizes using UV-resistant tie-wraps and #14 solid wire with crimp lugs for robust RF connections, bypassing the fiberglass rod for current flow. A bonus section details a 40-meter version, utilizing 48 turns of 8 TPI, 2-inch diameter coil stock.

A vertical antenna that can cover HF bands using an UN UN and a fishing pole, usage of tuner is requested.

A moxon antenna project for the 145 MHz

March Paddle by K4QU

This article will help to unravel some of the mysteries as well as giving useful operating tips to maximize your chances of working that rare station

A Working analysis of the gamma match problem that gives useful practical results in a article dated April 1969.

RCKLog is a windows freeware program for logging and administration of SSB and CW-Contest with simultaneous control of transceiver and real-time operation of Packet-Radio.

Cheap Antennas for the AMSAT LEO Kent Britain WA5VJB

An Off-center-feed antenna that covers 80, 40, 20, 17, 15, 12, 10, and 6 meters

Notes on Axial-Mode Helical Antennas in Amateur Service. Helix Basics, Modeling Issues, and Short Helical Antennas Over Perfect Ground

A free to download and print, paper log sheet useful for portable amateur radio operations, in a PDF file.

Every ham needs an RF power meter. Here is a high performance unit to build at home.

Transistor and its history and lot of related infos

How to operate on 10 and 20 meters in limited space with this trapped dipole.

This document details the design and construction of a Vinecom 6N4 dual-band Yagi antenna for the 50MHz (6-meter) and 70MHz (4-meter) amateur radio bands. The antenna features 9 total elements (4 elements for 50MHz, 5 elements for 70MHz) on a 4.236-meter aluminum boom. Computer simulations using MMANA software predict 7.21 dBd gain on both bands with front-to-back ratios of 16.01dB (6m) and 15.37dB (4m). The design uses 12.7mm diameter elements mounted on a 32mm square boom, weighing 5.7kg total. Practical measurements with an MFJ-269 analyzer confirmed good SWR performance across both bands after element length adjustments.

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.

5 elements Yagi antenna with an 8.7 db gain

A PDF presentation of a home made moxon antenna for 50 MHz 70 MHz and 144 Mhz. The project is mainly out of surplus plastic Plumbing pipes and clips etc, and also details of how the dimensions were calculated.

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

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

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.

An active receiving antenna for 10 KHz to 20 MHz, a very small sized antenna with excellent performances in noise to signal ratio.

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

Homebrew a compact yagi antenna for 14 Mhz suitable for those with small plots based on a design by AB4GX

A sourge arrestor for PL 259 connectors. A voltage surge arrestor to limit the voltage that may come back down the wire or coax after there has been static build up

A home made yagi antenna featuring 6db forward gain and 22 Db front back

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

Build this cheap and easy satellite downlink antenna

A solutiom for the Ameritron AL-811(H) RF power amplifier, burnt panel meter lights. A common failure with the Ameritron AL-811 and similar amplifiers is that the panel meter lights burn out prematurely. These bulbs are usually integrated into the actual panel meter. The solution for this is to provide the meter backlighting with LEDs.

Adding extra directivity to the Moxon Rectangle for 6m, 4, and 2m