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A presentation of a HF multi-band sloper antenna. This antenna project is for low band operations, and antenna presented in this article works on 40 80 and 160 meters band. Article is in Polish.

VHF Power amplifier VLA 200 english manual

2 transistor transceiver for 28MHz CW

PIC micro controller based frequency counter with LCD readout

Download the Yaesu VX-8R Cheat Sheet PDF File

Designing and constructing portable wire antennas for HF operations, this resource explores several configurations including the _foldback dipole_ for space-constrained setups and an inductively shortened dual-band dipole for 20m and 40m. It details the calculation of inductance for shortened elements, providing a Visual Basic 6.0 program screenshot that illustrates determining coil parameters like turns and length for a **25.5 uH** inductor. The document emphasizes practical considerations such as adjusting wire lengths for optimal SWR, noting that a dual-band dipole achieved SWR below 2:1 on both 20m and 40m, with careful adjustment bringing it under 1.5:1. Further, the resource describes a half-wave antenna matched with a coaxial stub, a method often referred to as the _Fuchskreis_ in German amateur radio circles, to transform the high feedpoint impedance to 50 Ohms. This monoband solution, for a 20m application, uses a stub length of **2.98m** (0.216 lambda multiplied by coax velocity factor) and a shorted stub of approximately 48cm. The coaxial stub design is highlighted for its resilience to ground proximity, allowing it to be rolled up or laid on the ground with minimal SWR impact, making it highly suitable for portable QRP operations.

Tips on winding wire coils used as inductive loads, traps, band-pass filters, are implemented in a number of amateur radio projects especially antenna projects

70 MHz transverter, 4m band, by G3XBM

My Top Five Backyard Multi-Band Wire HF Antennas. A selection of the top 5 HF wire antennas for the backyard and for multi-band operation

Photo construction manual of a portable antenna made with two heavy duty whips by buddipole. In this article has been implemented a 50 MHz portable dipole.

Review of Cushcraft MA-5B multiband Antenna after some days of usage.

Project for DXers and experimenters alike. An old article publishes by 73 Amateur Radio magazine in PDF format, where all the components required to build your own HF spectrum analyzer may be found in a well-stocked junk box.

Find out how much to adjust the length of a quarter wave whip or a half wave dipole rather than the outright cut-and-try method.

Printable Quick Reference Card for Yaesu VX-7R

Building a Windom HF Antenna. A PDF file presentation about homebrewing a windom antenna for the HF bands with formulas for 40 and 80 meters bands and step by step guide on making a 4:1 balun to feed the antenna.

Accurate frequency measurement is crucial for amateur radio operators, particularly when building or troubleshooting transceivers and test equipment. This resource details the construction of a _PIC microcontroller_-based frequency counter, providing a practical solution for precise frequency display. The design incorporates an LCD readout, offering clear visual feedback of measured frequencies. The counter can operate as a standalone unit, useful for general bench testing, or be integrated directly into a receiver. Its built-in offset functionality allows for seamless integration, enabling the display of the received signal frequency rather than the intermediate frequency. The project focuses on accessible components and construction techniques, making it suitable for homebrew enthusiasts. Key features include a measurement range up to **50 MHz** and a compact form factor.

The resource details the construction of a multiband trap-style Inverted-V antenna designed for operation on 3.5 MHz, 7 MHz, 14 MHz, 21 MHz, and 28 MHz. It presents specific winding data for the traps, including the number of turns, wire gauge, and coil former dimensions, crucial for achieving resonance on the target bands. The document provides a parts list and a diagram illustrating the antenna's physical layout and trap placement. It outlines the process for building the traps using PVC pipe formers and specifies the required capacitor values for each trap. The design emphasizes a practical approach to achieving multiband operation with a single feedline, a common goal for HF operators with limited space. The document includes a table with antenna segment lengths for each band, allowing for precise replication of the design. It also offers insights into tuning and adjustment, ensuring the antenna performs optimally across the designated amateur radio bands.

A home made 4:1 Ferrite QRO Bal-un with a FB 241-61 Type K

W5UXH version of OZ1JHM Morse Code decoder project

Skin effect and proximity effect on making coils with stranded wire. An interesting comparison on making coils.

An interesting article on guanella baluns that cover several aspects of homebrewing 1:1 and 4:1 current baluns by KN9B

Quarter wave groundplane antenna for 2 meters FM by AA1PG

May 2015 Radcom Article on common-mode chokes that can be used for control cables, phone lines, but mostly on typical HF antenna systems. This article explain what common mode chokes does, why you meay need one, properties common mode chokes should have, how to build and measure performances.

Construct a compact, 20 meter rotatable dipole antenna of durable weather worthy components supported at a single point obviating the need for multiple supports and multiple support ropes crossing the yard.

Repair LDF Z-100 toroid by VK4ADC

Diamond W8010 Multiband Dipole Modifications

QST Magazine, 1991 July, review of the Kenwood TS-850S 160-10 Meter Transceiver

The Ameritron ALS-600 600-Watt HF Power Amplifier review by AD5X

Ameritron QSK 5 PC mod for AL80B

50MHz Collapsible 2 Element Mini Beam antenna, an overview the development of the 6MBA.

This article is about a simple vertical end-fed-half-wave wire antenna for 10 meters that can be used in case of restricted space.

A handy piece of test equipment useful for HF bands, can absorb a 200W modulated carrier for almost 2 minutes. It is housed in a tin and part filled with dry sand that helps in power dissipation

Globe-S for RTL1090 is a light radar viewer for RTL1090. It communciates via a HTTP interface and can be interfaced over long distances.

IARU Region 3 bandplan Revised 12 March 2019

VK Contest Log (VKCL) is a free contest log software specialising in Australasian contests but also covering some international ones too. Author is SK, you can donwnload the latest version 4.15.

An ham radio contest log sheet in a PDF US letter printable format, can be used for portable operations, free to print and download.

In this article the author provides some guidelines on how to solve a common problem when stacking different types of yagi antennas on the same mast, limiting the effects on gain and radiation pattern of both antennas

Calculate the value of an unknown resistor with this free program for windows

This app will give you a 16 tone DTMF keypad and the ability to generate custom DTMF sequences, and set the duration and tone to silence ratio. Includes the characters 1234567890*# and the menu tones ABCD. You may enter a custom sequence via the keypad, soft keyboard, or speech if your device already has speech-to-text capability. This is basically a touch tone telephone keypad, which may be of interest to amateur ham radio repeater operators

Six elements yagi antenna for 6 meters band. This antenna design is based on the QuickYagi 4 software by WA7RAI, uses a 6.5 m boom, feature 12.0 dBi gain and 35dB front/back

Layman level explanations of "seemingly" mysterious LF MF and HF propagation occurrences.

A transceiver front-end protector in high signal level environments. An homemade RF limiter to protect your receiver front-end from high radio frequency.

This sweeper built for a narrow bandwidth filter adjustment, use a simple 555 version sawtooth wave generator.

A complete guide to undestand and know how electret condensor microphone elements works by K3DAV

Manually programming D-Star handheld transceivers like the _Icom ID-51A_ and _ID-31A_ can be a straightforward process, enabling operators to configure repeaters, simplex frequencies, and D-Star specific settings without relying on computer software. This method is particularly useful for field operations or when quick adjustments are needed, allowing hams to set up callsign routing, DR mode, and reflector links directly from the radio's interface. Understanding the menu structure and key sequences is crucial for efficient on-the-fly programming. Operators often find manual programming invaluable for activating new D-Star repeaters encountered during travel or for participating in local nets where specific G2 or G3 gateway configurations are required. While software like _CS-51_ offers convenience for bulk programming, the ability to manually input frequencies and D-Star parameters ensures operational flexibility. This approach also helps hams troubleshoot connectivity issues by verifying individual settings directly on the transceiver, ensuring proper D-Star registration and gateway access.

Study of the Coaxial Dipole: Just how does this thing work.

QRQ or Copying CW over 70 wpm

Experimenting vertical wire antennas for 40 and 20 meters supported by balloons resulting in excellent gain in RX and good overall performance against horizontal dipole

Homebrewing a Gamma Match to tune yagi antennas

Receive and listen to FM and AM radio broadcasts on your browser or ChromeBook using an RTL2832U-based USB digital TV tuner.