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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.

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

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

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

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

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.

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

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

Adding an external antenna to the Belkin F5D7050

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

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.

N3OX 80m/160m rx loop

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

Project by VE7GC

Schematic for a DIY 70 cm vertical antenna

Experience of band filters, for a contest multi operator enviroenment

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

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.

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

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

The free pdf book is a compilation of articles congenial to QRP published on 2003- 2005 years at free e- magazine AntenTop. 17 Mb pdf file.

Yo5ofh j-pole antenna plans for 2 and 6 meters

This free windows application is used for simply triggering PTT via DTR/RTS COM port pins. It supports remote PTT triggering with ptt2dtr as the server.

40mm diameter grey PVC pipe with a length of 9.5cm

This Arduino project decode ICOM CAT frequency information and switch antennas according to preset values. RX and TX antennas can even be different, a project by ON7EQ

The ARRL page, titled "The HF Mobile Antenna," serves as a curated index to various _QST_ articles focusing on constructing mobile HF antennas. It presents several projects for the mechanically inclined amateur, suggesting that homebrewed antennas can achieve efficiency comparable to commercial versions. For instance, one entry details a **five-band** antenna for RVs, utilizing a fold-over Hustler 4BTV, while another describes a "Bug Catcher" design for 80 through 10 meters. Further projects include a budget-friendly $20 HF mobile antenna made from PVC and wire, covering 20 through 6 meters, and the "Alpha Special," a multiband horizontal antenna originally for 1960s station wagons, now suggested for mini-vans. The resource also addresses antenna mounting solutions specifically for travel trailers and campers, providing practical insights for those operating from recreational vehicles. Rounding out the collection are the "Connecticut Longhorn," a 75-meter horizontal whip with remote tuning, and its redesign, the "Connecticut Shorthorn," adapted for smaller vehicles post-1970s. This compilation offers a historical perspective on mobile antenna innovation and practical construction guides for various HF bands and vehicle types.

The page describes the construction of a simple omnidirectional, vertically-polarised dipole antenna for two metres using coaxial cable. It can be used indoors or outdoors, with no extravagant gain claims. The project is low-cost and can be completed in about 20 minutes.

The I0JXX is an italian company that offers market their projects, also sells electronic products of high quality, both for Ham, both Broadcast and their accessories. VHF Antennas, mosfet power amplifiers, filters, insulators, power dividers, telescopic poles, antenna masts

The 20m monoband 4-1000 amplifier, by Jelmer (pa5r), Herman (pa0ten) and Frans (pa5ca)

This program simulates a HF link, using sound card and WIN95 by Michael Keller, DL6iAK

Communication Concepts, Inc. specializes in providing RF components for both amateur radio operators building their own gear and professionals prototyping circuit designs. The inventory includes a range of products such as HF and VHF amplifiers, splitter combiners, and various filters, catering to diverse applications from QRP to high-power systems. The site details specific components like _Freescale_ and _Motorola_ RF transistors, along with custom semi-rigid coaxial cable options. The offerings extend to parts for ATV, packet radio, and general electronic components, emphasizing quality and service since 1979. Customers can find items like low-pass filters for RFI/TVI mitigation and specialized transformers for RF power systems, covering frequencies from 2-30 MHz Type "H" to 1-80 MHz high-power applications. The resource highlights its role as a supplier for those constructing custom radio equipment, offering components that facilitate projects from basic radio kits to advanced amplifier designs, with a focus on enabling self-construction and cost-effective prototyping.