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VHF, UHF, FM, Base & Mobile antennas

The Homebase10 is a simple to make wire halo antenna for 10m (28MHz) built using parts available from the local DIY store.The resulting antenna is very effective on 10m despite its small size and light weight.

HF power amplifier project by YB0AH

A one-tube battery-powered regenerative receiver.

Presents a comprehensive guide for constructing a broadband Hex Beam antenna, a popular directional array for HF operation. This design offers a compact footprint and excellent gain characteristics, making it suitable for limited space installations while providing significant performance advantages over omnidirectional antennas. The resource details the specific dimensions for a five-band Hex Beam covering 20, 17, 15, 12, 10, and 6 meters, emphasizing the critical element spacing and wire lengths required for proper resonance and pattern. It outlines the construction of the center post, spreaders, and wire elements, along with the feed point assembly, ensuring proper impedance matching. The project aims for a forward gain of approximately **5.5 dBi** on most bands, with a front-to-back ratio often exceeding _20 dB_. Building this antenna requires careful measurement and assembly, but the resulting performance provides a substantial upgrade for DXing and contesting.

Engaging in **QRP** operations, where amateur radio transceivers transmit at five watts or less, presents a unique challenge and satisfaction for many radio amateurs. This mode emphasizes efficient antenna systems, keen operating skills, and often, the art of **homebrewing** equipment to maximize performance under power constraints. Operators frequently utilize CW (Morse code) for its superior signal-to-noise ratio, enabling reliable contacts over long distances with minimal power. The VK QRP Club, formally known as the CW Operators' QRP Club Inc., serves as a focal point for Australian amateurs passionate about these low-power pursuits. The club fosters a community where members can share insights on antenna design, circuit construction, and operating techniques specific to QRP. It provides resources such as information on club nets and frequencies, Morse practice materials, and a platform for exchanging ideas among enthusiasts. Membership offers access to a network of like-minded individuals, promoting the continued development and enjoyment of QRP within the amateur radio hobby. The club's activities encourage experimentation and skill refinement, vital aspects of successful low-power communication.

no tune SSB/CW transceiver for 1296, 2304, 5760 and 10368 MHz

This page shows a homebrew vertical antenna based on the Pac-12 antenna design.

YF1AR 80 to 40 meter vertical antenna project

The Antenna Rotator Controller is unique in that it senses, displays, and controls to the earth's true magnetic field. The compass sensor, mounted in a waterproof enclosure, is attached to the mast and sends its signal to a microcontroller

Two 50 Mhz amplifiers and antenna switch

The Upside-Down Umbrella Antenna by Don Keith N4KC

VHF quad antenna for transmitter hunting.

An home made trapped dipole antenna for 40 and 60 meters band by 2E0HTS

UM58 a regenerative receiver project

An interesting article about co-linear or collinear antenna building, by Karl Shoemaker, AK2O

It's a whole new way of preparing for the government FCC License examination. The classroom is your home.

Presents the detailed construction of the _FLA25HV_ antenna, a specialized array optimized for Earth-Moon-Earth (EME) communications on the 2-meter band. This resource provides schematics and practical insights into building a high-gain antenna system capable of reflecting signals off the lunar surface, a challenging but rewarding aspect of amateur radio. It covers the mechanical and electrical considerations essential for achieving the precise pointing and signal strength required for successful moonbounce contacts, often yielding **20 dB** or more gain. Amateur radio operators pursuing EME operations require robust antenna systems and precise tracking capabilities. The FLA25HV design addresses these needs by focusing on element spacing, impedance matching, and structural integrity to withstand environmental factors while maintaining critical alignment for lunar reflections. Such systems are crucial for making contacts over distances exceeding **768,000 km**. This personal page serves as a practical guide for hams interested in constructing their own EME arrays, offering a glimpse into the technical dedication involved in pushing the boundaries of VHF/UHF propagation.

VHF/UHF DX site showing latest propagation, software, radio dealers, awards, maps etc.

A 3.5 Mhz top loaded vertical antenna built using 2 elevated radials by DJ9RB

Shortwave dxing newsletter, Cumbre DX is dedicated to reporting what's hot in regional and international shortwave broadcast listening

Make yourself a Diplexer

Circuits, pictures and data about toroids, tubes and home made power amplifiers

Demonstrates the essential steps for winding **toroidal cores**, a fundamental skill for amateur radio operators engaged in homebrewing and kit building. It addresses the critical aspects of selecting the correct core material and wire gauge, emphasizing the importance of precise turn counting and consistent winding tension to ensure optimal circuit performance. The resource details methods for preparing the wire, including techniques for safely removing enamel insulation from leads using flame, sandpaper, or a solder pot, and provides guidance on tinning the exposed wire. Explains the process of mounting the wound toroid onto a printed circuit board, highlighting the need for careful lead placement and secure soldering to prevent shorts and ensure mechanical stability. It also offers a practical formula for calculating the required wire length based on the desired number of turns and the specific **toroid** size, referencing common core types like T-50 and FT-240. The guide stresses the importance of verifying the inductance of the wound component, often using an inductance meter, to confirm it matches design specifications. Provides practical tips for handling multi-filar windings and managing short lead lengths, which can be particularly challenging. It underscores the necessity of meticulous attention to detail throughout the winding and installation process to achieve reliable and efficient RF circuits.

A page dedicated to the doble bazooka antenna with dimensions for all HF bands

A 400 W 144 MHz GI7b Linear amplifier

Circuit diagrams to homebrew different baluns by vk2awx

Constructing a functional spectrum analyzer for the 0-100 MHz range presents a significant challenge for radio amateurs, often requiring specialized components and careful calibration. This project details a homebrew spectrum analyzer design utilizing common integrated circuits like the _SA605D_ FM receiver IC and _MAR-6_ MMIC amplifiers, aiming for a cost-effective solution. The design incorporates a low-pass filter, RF amplification, a voltage-controlled oscillator (VCO) for downconversion, and multiple IF stages at 150 MHz and 10.7 MHz, with a resolution bandwidth (RBW) of 15 kHz. Critical components such as the _SBL-1_ mixer and varicap diodes are specified, alongside instructions for winding inductors and tuning filters. The analyzer's performance is discussed in terms of input level limitations, specifically the 1dB-compression point and third-order intercept point, to ensure accurate measurements and prevent component damage. The _SA605D_'s logarithmic Received Signal Strength Indicator (RSSI) output serves as the detector, driving the Y-input of an oscilloscope, while a _TL084_ op-amp generates the sweep signal for the X-input. Potential enhancements include adding a step attenuator, improving front-end filtering, and implementing switchable IF filters for variable RBW, allowing for greater versatility in analyzing RF signals.

VU2VWN project to homebrew a CW for 40 meters band

Build an HF antenna tuner by VK5AJL

Sharing information on Topband Homebrew Antennas, Base & Mobile

An RF power supply for 144 MHz schematics and instructions

PA5DD version of the dual band yagi antenna for 50 and 70 Mhz

Time to show your TV who's boss

CW paddle made with a steak knife some simple hardware and a stainless steel fork

My first homemade SSB and CW receiver 10 kHz to 30 MHz

German page about packet radio, english version available

Transverter for 70MHz, a project by G3XBM

A project for a homemade multiband Hexbeam antenna for 10, 12, 15, 17 and 20 meters

Comprehensive astronomy / space / satellite-tracking package for Microsoft Windows 95/98/Me and Windows NT 4.0/2000/XP

VU3NSH article on high current universal supply for rigs

A solid state linear based on EB104 Motorola Engineering Bulletin by Helge Granberg. It uses 4 MRF150 FETs in push-pull parallel to acheive 600 Watts from about 6 Watts drive

Club dedicated to the world of Hellschreiber

Homebrew Wifi antenna test page

Learn the Morse Code. Learn from random text or simulated QSO (contact) sources. Create character sequences that you find difficult. Compare your results with what the program sent and view error statistics. Take simulated tests. Sound card not essential. Evaluation version not time limited.

An Arduino project to make it work as a KISS TNC

An impedance transformer (9:1) to feed a high impedance long wire (~450 ohm), down to a 50 ohm unbalanced coaxial input.

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

Home made RF power amplifier for six meter band

An inexpensive condenser microphone with excellent performance can be easily constructed with easily available parts.