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Article and comparison between bazooka antennas and dipole, taking care of effieciency and bandwidth

By Dave Gauding, NF0R

This was a project to make a dummy load or, as the finished thing is more correctly labelled, a fifty ohm resistive load.

Schematics and plans to build a custom CAT and audio pc interface

Over 45 years of amateur radio experience inform the homebrew projects detailed on this personal website, with a particular focus on microwave frequencies. The site showcases a 24 GHz transverter and a more recent 47 GHz transverter, demonstrating practical construction techniques for extreme high-frequency operation. These projects often involve custom circuit design and careful component selection to achieve stable performance at millimeter-wave bands. Key projects include a _harmonic converter_ for frequency measurement and a tracking spectrum analyzer, essential tools for microwave experimenters. The site also documents a CW sidetone generator and a TX/RX sequencer, illustrating fundamental building blocks for radio equipment. Details on a digital frequency meter and an S-meter/dBm meter provide insights into test equipment construction. Specific achievements, such as a **24 GHz** tropo QSO with DK3SE in 2021, highlight the operational success of these homebrewed systems. The content reflects a long-standing dedication to self-sufficiency in amateur radio, providing practical examples for those interested in building their own gear.

Described here is a simple omni-directional, vertically-polarized dipole for two meters. Made from coaxial cable, it can be rolled up and stored in a small container

Article on building a folded bazooka antenna

Build parabolic WLAN antenna adapted from a small satellite dish. It provides high gain and long range connections.

A simple keyer which can be built for as little as $6 with some junk box parts. Although this circuit is not a true iambic keyer, it is capable of producing perfectly sounding CW.

Ham Radio applications with the Arduino micro-controller presentation

Technical reference about Accessories, Amplifiers, Antennas, Cable and Connectors, Filters, Geography, Grounding, Gunk, Matching Networks, Projects, Propagation Info Radios, RFI/EMI, Rotors, Station Setup, Towers.

This project describes an ARDUINO based automatic antenna tuner, for an end-fed half wave (EFHW) antenna, working on 20 & 40 meter bands

by Mike Martell N1HFX

Unified Microsystems presents a range of amateur radio products, notably the **XT-4 MK2 CW Memory Keyer**, a battery-powered iambic keyer designed for portable operations like Field Day, POTA, SOTA, and DXpeditions. It features four non-volatile memories, each storing approximately 240 Morse characters, and operates at speeds from 8-45 WPM. The XT-4 MK2 also includes an auto power save function and paddle reverse, making it adaptable for multi-operator setups. Beyond the XT-4 MK2, the site details the **W9XT Contest Card**, a PC plug-in board offering DVK and CW interface capabilities, allowing operators to record and playback CQs and contest exchanges. Other offerings include the BevFlex-4X RX Antenna System, RAS-4 RX Antenna Switch, VK-64 Voice CW Keyer, and various USB interfaces. Additional products cover electronic development, such as the ATS-1 Terminal Shield for Arduino™ and VR-X Power Supply Voltage Regulators, demonstrating a broader scope beyond just operating accessories. The XT-4Beacon MK2 / CW IDer is also highlighted for beacon projects, capable of storing messages up to 5 minutes at 25 WPM.

CuteSDR Open-Source application for MacOSX , Linux, and Windows designed to run with RFSPace SDR receiver

Constructing a high-power solid-state amplifier for HF operations presents unique challenges, particularly when aiming for significant output like 600 watts. This project details an amplifier design employing **Motorola MRF150** FETs, a common choice for their robust performance in RF power applications. The design emphasizes achieving substantial power output, a critical factor for effective DXing and contesting, where every decibel can make a difference in signal propagation and readability. While specific circuit diagrams or construction details are not directly presented on the current page, the mention of MRF150 FETs points towards a design that would typically involve push-pull configurations, impedance matching networks, and robust power supply considerations to handle the high current demands. Such amplifiers are often built with an eye towards linearity and efficiency across the HF bands. Amateurs pursuing similar high-power solid-state projects often share insights on thermal management, intermodulation distortion, and component sourcing, all vital for a stable and reliable amplifier capable of delivering 600 watts into a proper antenna system.

These devices are called Traps, but they are actually more like frequency sensitive switches. They are parallel resonant, high Q, tuned circuits which provide a very high impedance at their frequency of resonance.

Use plain water with a little salt added to build your own Dummy Load

KF4SCI picture of a project for a VHF UHF jpole antenna working on 220 and 440 MHz.

Adding an external antenna to the Belkin F5D7050

JTDX is an open-source software application for amateur radio weak-signal digital communication. It supports digital modes including FT8 and JT9. The software operates on _Windows_, _Linux_, and _macOS_ platforms. JTDX is designed for improved decoding of weak signals, a function also performed by WSJT-X and MSHV. The software facilitates weak signal decoding and transmission. It integrates with logging systems for QSO management and can automate tasks such as call management and remote RTX control. JTDX is utilized in contexts such as DXing and contests. DXZone Focus: FT8 | JT9 | Weak Signal | Multi-platform

Easy to use double tone IQ-generator for testing direct conversion SSB-transmitters based on phasemethod etc.

Get KB1OIQ - Andy's Ham Radio Linux CD at SourceForge.net. Fast, secure and free downloads from the largest Open Source applications and software directory

N3OX 80m/160m rx loop

An open source software decode various xMBE based modes. It support decoding QPSK, C4FM modes such as P25 Phase 2 (TDMA), MotoTRBO, NexEDGE, ProVoice and others more.

The Bazooka-antenna was developed by the staff of M.I.T. for radar use. The original Bazooka used coaxial cable for the entire radiating elements.

Double tone generator for testing intermodulation

A Moxon rectangle antenna projects for the 6 10 15 17 and 20 meter band but include drawings, plans, statistics and homebrewing statistics.

Project by VE7GC

Experience of band filters, for a contest multi operator enviroenment

When one operates at low power on SSB, speech processing becomes almost essential to get through the QRM. The circuit is a low cost speech processor that will perform well with a minimum of construction effort.

On 23cm the best way to obtain a good RX-sensitivity is to use a GaAs-FET in the front-end, since these devices show very low noise figures.

A Moxon rectangle antenna for 17 and 20 meters band

Schematic for a DIY 70 cm vertical antenna

Cancelling out unwanted noise sources by DL3FP

Signal Generator (VFO) with Direct Digital Synthesis by Bruce AA0ED and Craig AA0ZZ

Well documented Amateur Radio HF/VHF antenna projects, high power Russian GS35B RF amplifiers, mobile RFI solutions, related accessories, vintage radios, Six meter equipment, and useful techniques by K8CU are inside.

A DDS VFO using the Arduino Uno platform

Easy circuit that provide good gain to weak audio signals

Several projects which will allow you to build your own RF design test equipment.

The document discusses a two-element parasitic Delta-Loop array for the 40 meters band, aimed at radio amateurs interested in antenna projects. It provides detailed plans and instructions for building a homemade Delta-Loop antenna.

80m hexfet power amplifier by W7ZOI

The webpage provides information on a two-element Yagi antenna for 24 Mhz, created by IK4DCS. It includes details on the design and construction of the antenna.

The CW Decoder program facilitates copying Morse code with a computer, displaying decoded CW as text, and generating a sidetone. It incorporates a spectrum display of the audio, allowing operators to select a specific audio frequency for decoding via a sliding cursor. This utility also enables keyboard-based transmitter keying, supporting full CW break-in operation for efficient QSO management. Developed by WD6CNF, the software is a Windows-compatible application designed to assist amateur radio operators in their CW activities. Its features cater to both decoding received signals and transmitting via keyboard input, streamlining the CW operating experience. Functionality includes real-time audio analysis and signal processing, providing a visual representation of the CW signal. The program's integrated keying capability offers a direct interface for transmitting, enhancing its utility as a comprehensive CW station tool.

3 to 12 MHz signal generator, simple local signal source

The Windom antenna was widely used in the 1930s and is named after the amateur that wrote a comprehensive article about it

VHF, UHF page, technical articles, projects, datasheets

Rhombic antenna experiments by Jelmer PA5R

Constructing a linear focus parabolic antenna for WiFi operation involves precise metalwork, as detailed in this project. The author, AB9IL, shares a build that can be completed in a few hours, emphasizing the hands-on process of shaping and assembling metal components. This design aims to provide enhanced signal range for 2.4 GHz wireless networks, a common challenge in many ham shacks and home setups. The project outlines the practical steps required, from initial measurements to the final assembly, including cutting, bending, and bolting various metal parts. While specific gain figures are not provided, the parabolic design inherently offers significant _directional gain_ compared to omnidirectional antennas, making it suitable for point-to-point links or extending network coverage over distances. The construction process focuses on readily available materials and basic shop tools, aligning with the DIY spirit prevalent in amateur radio. This antenna project is presented as a straightforward build, requiring attention to detail in fabrication to achieve optimal performance.

This signal generator is intended for realignment of radio receivers