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F5DQK repairing and swr measurement tests of a Cushcraft R7 Antenna

This is a 6 band receive only filter designed to protect your receiver front end and provide 45dB reject at the stop bands. This is a 6-band receive only filter designed to protect your receiver front end and provide 45dB reject at the stop bands. Stop band reject may be limited by the relay isolation. Worse case isolation is at 28 MHz or 35 dB or better. Relay K3/K8 protects the filter during transmit via the PTT line. A 25-50ms delay must be used between transmit and PTT. Do not rely on your radio to provide adequate delay with out using the PTT. You logging software must be set to allow a delay between PTT and time of 1st transmit. This filter will not work with VOX or QSK keying as you will damage the filter.

KG4JJH moxon assembly plan for the 50 Mhz in a pdf file

Club dedicated to the world of Hellschreiber

The problem with making your own trapped HF antennas is usually getting the coaxial traps tuned to frequency.

Lighting protection document by Glen E. Zook

An Arduino project to make it work as a KISS TNC

An easy mod to make the 1st IF of the Icom IC-7600 accessible and connect to a cheap RTL SDR dongle by VE4NSA

The HF ham bands can be mysterious. Some work at night, some during the day. Some seem to be good for long distance contacts while some are better for nearby contacts. Even worse, they change tremendously from hour to hour and day to day. An overview on operating on HF amateur radio bands

A moxon antenna project for 70 cm band, test and results of this popular antenna model applies to UHF bands.

CWQSO allows you to practice sending and receiving CW in a real QSO!

The Wireless Institute of Australia (WIA) provides an official directory and database of Australian amateur radio repeaters, detailing their locations, frequencies, and operational status. The resource includes downloadable files in PDF and CSV formats, along with a _Google Earth KMZ_ file for visualizing repeater sites across Australia, including Amateur, CB, and Marine repeaters. It also references external resources for various digital modes such as _IRLP_, _Echolink_, _D-STAR_, P25, Fusion, and DMR, providing links to their respective information sites. The WIA repeater data is cross-referenced with the _ACMA database_ to ensure accuracy, with updates typically occurring twice a year. The directory employs a color-coding system, where purple indicates repeaters carrying the WIA broadcast or callback channels, and a 'W' status denotes operational repeaters with the weekly WIA broadcast. The resource also outlines policies for removing unlicensed or non-operational repeaters from the PDF listing after specific timeframes, while retaining them in the CSV file for potential reinstatement.

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.

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

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

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

GM3VLB Mini delta loop antenna

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.

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

This grid locator map uses Google map apis to find your QTH locator by simply clicking on the map. You can either enter your QTH locator and find the calculated distance and bearing between your QTH and another grid square.

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.

A small antenna for limited space / lanai use.

A simple antenna tuner for 4m by Tony Hawker G4CJZ

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

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

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

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

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

A junkbox bugstick for 20m, 17m, 15m, 12m, and 10m bonus at the bottom a junkbox bugstick for 40m

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

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

March Paddle by K4QU

A moxon antenna project for the 145 MHz

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.

Shortwave Radio Schedules from Eibi/AOKI combined lists. Includes Google maps showing beam directions and long paths.

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.

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

Transistor and its history and lot of related infos

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.

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.

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