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This is not a sophisticated automatic keyer but it is lot QRP to build and to have fun operatin

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.

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.

Useful hints & tips on building a 10 and 17 meter Moxon Antenna

Constructing a Compact Low Cost Sprinkler Valve Antenna Launcher

This antenna article is geared towards new Hams and antenna builders looking for a very inexpensive 6 band antenna that can be efficiently fed with 50 ohm coax without a tune

How to build a QFH (Quadrifilar Helix Antenna) to download images from weather satellites. A complete tutorial on assembling QFH antenna at home with simple and common tools

A 38-foot Tristao Tower, similar to the U.S. Tower HDX538, was installed twice by the author, first in 1980 and then reinstalled in 1989. The resource details the challenges of self-performing heavy construction tasks like breaking concrete and digging a 3' x 3' x 6' deep footing, contrasting it with hiring professionals for the second installation. It highlights the financial and physical costs associated with DIY tower foundation work, noting a rebar cage cost of $65 in 1980 versus $150-$175 today, and the expense of tools for bending rebar. The content emphasizes the critical importance of obtaining building permits, recounting how a permit in Buena Park, California, nullified a neighbor's complaint about TVI. It also discusses the necessity of adhering to local building codes, such as the 1975 UBC and the subsequent 1985 UBC recertification requirement, which reduced the allowed antenna wind loading from 30 square feet to 20 square feet for the author's _KT34A_ Yagi. The footing depth also increased from 6 feet to 6.5 feet under the newer code. Practical advice includes hiring licensed contractors for specialized work, delaying antenna installation for a month after raising the tower, and verifying buried utilities before any excavation. The author provides specific examples of utility location services like _DigAlert_ in California, underscoring the legal and safety implications of neglecting this step. The narrative is grounded in personal experience, offering a realistic perspective on tower projects.

The use of dummy load is mandatory for off-air adjustment of the transmitters. Build one.

Building the MFJ Cub QRP transceiver kit for 20 meters band by G4ILO

Do you want to measure antenna impedance at resonance? With this Antenna Scope, you have a simple RF Bridge for getting started in an exciting part of Ham Radio, building your own Antennas that work well

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.

Building a Resonant Feed line Dipole for 2 Meters

From the Publishers of EPE, this specialist niche publication is of interest to vintage radio enthusiasts, offering step-by-step rebuilds of selected receivers and helpful ideas and advice. Published every other month, each issue contains articles on radio restoration and repairs, histories, circuit diagrams, nostalgic memories and adverts by specialists.

Presents the construction of a 2-meter **Skeleton Slot Yagi** stack, detailing the design process and practical considerations for VHF operation. The author shares insights from building and testing this antenna, emphasizing its performance characteristics for local and extended range contacts. The project outlines the specific dimensions and materials used, providing a clear path for other radio amateurs to replicate or adapt the design for their own stations. The resource covers the unique aspects of the Skeleton Slot radiator, explaining how its geometry contributes to gain and pattern control. It includes discussions on impedance matching and feedline considerations crucial for optimizing power transfer and minimizing SWR. The article draws on real-world testing, offering practical results that validate the theoretical design. This project serves as a valuable reference for those interested in custom VHF antenna solutions.

A new, simple way to build the Eggbeater Antenna. This document introduces a new, simpler way to build the Eggbeater antenna. It also introduces a technically proper way to construct the Eggbeater antenna in order to achieve the best result.

An easy to build with a cheap HEMT FET Transistor Low noise preamplifier with FHX35LG based on JH0WJF design

Radio electronic and antenna consulting, servicing and buildups of customer supplied components. Transmitter and receiver site work and on line help.

An Easy to build and operate induction generator

Notes on how to build an inverted V wire antenna with lenghts for all HF bands from 160 mtrs to 10 mtrs

Easy to build CW decoder based on DSP Goertzel code. If you want to build a cw decoder without using other active components than an atmel 328, Arduino UNO, then this is sure something for you.

An interesting article about planning and testing beverage antennas for 80 and 160 meters in a rural location

Used in the Kenwood TM-241, TM-741 2m module by W3KKC

The range and coverage of your VHF transceiver will be limited to your radio horizon. How to calculate the visual horizon and how to determine the Radio Horizon

Homebrewing a Gamma Match to tune yagi antennas

This article describes how to build a general purpose DTMF decoder with a low-price chip from MITEL

High wind warning system, programmable, gives progressive series of alarms at three windspeed thresholds. Can be building-mounted or made portable for storm spotters, chasers, etc. Totally unique system!

Using Andrew FSJ1-50A 1/4" Superflex Heliax with PL-259 Connectors

US amateur radio antenna manufacturer, design and build monoband, dual band and multiband Yagi Antennas for HF bands as well as receive antenna systems

Amateur Radio 40m 20m 15m Half Wave Fan dipole antenna project with part list, pictures and drawing. Includes the option to expand the antenna to cover the 80 meters band

This method of construction can be used on most UHF through \"low\" microwave Yagis, and is especially useful for the 33, 23 and 13 cm bands

Projects you can build, an amplified shaped sine-wave oscillator

Constructing a high-power 70cm solid-state amplifier presents unique challenges, particularly when aiming for 500 watts output using modern LDMOS devices. This resource details the author's experience building a 70cm amplifier based on a _Freescale MRFE6VP5600H_ transistor, initially from an RFHAM kit. It meticulously outlines the necessary modifications to achieve advertised performance, including optimizing input and output matching, correcting bias circuitry, and ensuring proper output balun connections for stability. The author shares specific adjustments, such as trimming the prototyping board for better transistor fit, drilling additional mounting holes for improved heat sinking, and replacing original matching capacitors with a single _20pf MIN02 metal mica_ for superior output. A critical fix involved jumpering gate decoupling pads to balance the push-pull transistor halves, which increased output to 580W and improved IMD. The resource also highlights a crucial correction to the output balun connection, initially reversed in the _Dubus_ article schematic, which resolved intermittent stability issues. Test results are provided, showing input power, output power, and drain current at 50V, demonstrating the amplifier's performance after modifications. This practical account offers valuable insights for hams undertaking similar high-power UHF amplifier projects, especially those working with LDMOS devices and kit-based constructions.

A DIY Automatic Band Decoder (ABD) project, designed for dual-radio operation, addresses the common challenge of integrating band data with older transceivers lacking dedicated outputs. This particular build utilizes an AVR AT90S8515 microcontroller and a 16x2 Liquid Crystal Display (LCD) to provide band information, specifically targeting Kenwood rigs via a computer's LPT port. The design aims for cost-effectiveness while maintaining functionality, offering a solution for hams seeking to add automatic band switching capabilities to their station without significant expense. The project outlines the core components required, including the microcontroller, LCD, and an enclosure, noting that the Printed Circuit Board (PCB) fabrication and AVR programming might present challenges for some builders. It details the input requirements, such as a four-pin input and PTT for each radio, along with a 13.8V DC power supply. The decoder provides 2x6 outputs capable of sinking 500mA, suitable for controlling external devices like antenna switches or filters. Despite the original unit being damaged by a lightning strike in 2004, the author confirms its successful operation prior to the incident and mentions plans for a revised version. The resource includes a schematic in PDF format and images of the finished PCB and assembled unit, demonstrating the practical implementation of the design.

ozQRP offer a range of kits to build a complete QRP SSB transceiver

Soundmodem is a free software defined dual-port Packet-Radio TNC that implement a soundcard as a modem and supports AX.25 protocol. Soundmodem has been tested on Windows XP, Vista, 7, 8, 10 and has proved stable in operation. The Soundmodem may be used to build EMCOMM, APRS, BBS, Node station, for satellites

Presents Eagle Stainless Tube & Fabrication as a certified distributor specializing in various tubing products essential for antenna construction and other amateur radio projects. It details their offerings, which include aluminum tubes in fractional, metric, and heavy wall specifications, alongside stainless steel bar stock in round, square, and flat profiles. The resource highlights the availability of a diameter sizing chart and direct contact options for specialists, indicating a focus on providing specific material dimensions and expert support for custom fabrication needs. The company emphasizes its role as a supplier of raw materials, crucial for hams engaged in DIY antenna builds or structural components for their shacks. Their inventory supports the precise mechanical requirements often encountered in radio frequency engineering, where material strength, weight, and corrosion resistance are critical design factors for outdoor installations. The site primarily serves as a product catalog and contact point for sourcing specialized metal tubing and bar stock, providing technical specifications and material grades relevant to robust amateur radio infrastructure.

There are many designs for building preamps each with their own advantages and disvantages. In this PDF Article author reviews several different types.

Design and build a 6 meter 2-element Moxon antenna mostly from available aluminum tubing and angle stock.

Solar Power for Your Ham Station, It is Easier Than You Think QST article April 96 by KE0OG via Repeater-Builider.com

A project with schematic to build a receiver for 80 meters band by VK1PK

The m0xpd keyer project utilizes a PIC16F628A microcontroller, offering Iambic A and B modes, adjustable speed from 5 to 40 WPM, and variable weight control. It incorporates a sidetone generator with adjustable frequency and volume, along with a PTT output for transceiver control. The design includes a 16-pin DIL IC socket for the PIC, a 3.5mm stereo jack for the paddle, and a 3.5mm mono jack for the PTT output. Powering the keyer requires a 9V DC supply, which is regulated down to 5V for the PIC. The circuit board layout is designed for through-hole components, facilitating home construction. A detailed schematic and a parts list are provided, guiding builders through the assembly process. The project also discusses the firmware programming for the PIC16F628A, essential for the keyer's functionality. Construction details cover component placement and wiring, ensuring proper operation. The keyer's compact size makes it suitable for portable or shack use, providing a reliable CW interface.

Project with pictures and descriptions for building a portable 12 Volt DC power source by N1KXR.

Presents a construction project for a 1:1 current balun, specifically detailing the _Sorbie Balun and Bottle Choke_ design. The resource outlines the winding technique, employing 4+4 turns of mini coaxial cable on a large ferrite core, and provides insights into the physical assembly. It includes specific material recommendations, such as the type of ferrite and coaxial cable, crucial for achieving the desired impedance transformation and common-mode current suppression. The content covers the practical steps involved in building the balun, from preparing the coaxial cable to securing the windings on the ferrite toroid. It also discusses the integration of the balun into an antenna system, emphasizing its role in maintaining pattern integrity and reducing RF interference in the shack. The resource offers a clear, step-by-step approach, making the project accessible for homebrewers. Illustrations and photographs accompany the text, visually guiding the builder through each stage of construction. The article concludes with performance expectations and considerations for deployment, ensuring the constructed balun functions effectively across the intended frequency range.

Home build a Kenwood PG-5A cable. This lead is the audio data cable for some of the Kenwood Mobile transceivers

Design, build and supply Military Diesel Operated Tactical generator sets, diesel generator sets, custom generators, auxiliary power units, portable power generators and tactical quiet generators used by the U.S. Navy and Air Force.

The A QRP Club is a small group of Amateur Radio enthusiasts who enjoy building, operating and (mostly) talking about Low Power radio communications, equipment and systems.

This document is a must read for anyone considering building a good low cost HF multi-band antenna system. The author combine in this document four important ingredients to produce simple but effective antenna system, like antennas of non resonant length, line attenuation, the transmatch and the balun

This site is dedicated to those who enjoy building radios and other electronic devices using parts and techniques from bygone eras.

Ham radio HF antennas manufacturer, produce HF dynamic beam antennas, and vertical pole antenna. Offer kits and parts to build you own dynamic antennas, by IZ0AEG