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HA2NON W3DZZ antenna project with pictures and construction details

Constructing a **2-meter** J-pole antenna from readily available copper plumbing components offers a robust and cost-effective solution for VHF operation. This design, dubbed the "Plumber's Delight," functions essentially as a half-wave dipole fed by 50-ohm coax via a **gamma match**. It incorporates a quarter-wave copper tubing support, which, when affixed to a metal mast or tower, enhances forward power in the direction of the radiating elements. The original configuration utilized a small ceramic trimmer capacitor for the gamma match, suitable for up to 10 watts. A subsequent modification replaced this with a 50 pF variable capacitor housed in a plastic enclosure, accommodating higher RF power and improving weather resistance. The antenna elements are secured using a copper "T" fitting, and an SO-239 connector mounts directly to this fitting. Performance includes gain away from the support mast, and tuning is straightforward by adjusting the gamma match capacitor for a 1:1 SWR. The total cost for materials, excluding the capacitor and coax, can be under $10.

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

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

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

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

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

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

An interesting rotator interface that interfaces a pc to a rotor or rotator controller, emulating a Yaesu GS-232A/B and Easycom protocols, made with Arduino

Experience of band filters, for a contest multi operator enviroenment

The DRM Software Radio is based on the proven Fraunhofer DRM engine, which is considered to be the most advanced DRM engine today, built around fully licensed proprietary DRM encoding technology.

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.

Schematic for a DIY 70 cm vertical antenna

A Moxon rectangle antenna for 17 and 20 meters band

Cancelling out unwanted noise sources by DL3FP

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

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.

A DDS VFO using the Arduino Uno platform

Easy circuit that provide good gain to weak audio signals

A 5-band (20m-10m) HF antenna - Just 7ft square and great for a small garden. Build it yourself for around 60 GBP.

80m hexfet power amplifier by W7ZOI

AM loop antenna for 75/80 meters band

The DSP Satellite Transceiver is a conceptual transceiver designed as a dedicated unit for amateur satellite operators. The initial concept was brought about by the lack of satellite functionality on modern amateur radio transceivers, and the specialized requirements of the ham radio operator who utilizes OSCAR amateur satellites.

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

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

An Antenna Rotator Project. The rotor design is based on sandwiching the gears and gear supports between two 5/16 inch 6061 T-6 aluminum plates

A quarter-wave vertical antenna design for HF operation offers a practical solution for radio amateurs seeking a compact and efficient multi-band radiator. This project details the construction of a 5-band HF vertical, drawing inspiration from established commercial products such as the _DX COMMANDER_ and the MV6. The design emphasizes ease of assembly and disassembly, making it suitable for portable operations or installations with limited space. The article provides insights into various construction methods and offers practical tips for building a robust yet lightweight antenna. It highlights the benefits of a vertical configuration for DX contacts, particularly on the lower HF bands, and discusses real-world performance observations. The antenna is designed to cover multiple HF bands, providing versatility for various operating scenarios. Operators can achieve significant DX results with this type of antenna, often comparable to more complex arrays, especially when deployed with an effective ground system. The project aims to empower hams to build a capable antenna without significant financial outlay.

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.

Don't buy or build a semi-vertical trap antenna until you read this article! If you can use a drill, saw and screwdriver this is a simple project.

Run an oscilloscope under your Android phone

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

A short wave regenerative receiver project by Charles Kitchin, N1TEV

6x2 coaxial remote antenna switch, completed unit showing weatherproof relay box and station control unit.