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Ham Radio applications with the Arduino micro-controller presentation

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

by Mike Martell N1HFX

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

A PIC16F876 based, automatic 1.8 to 60 MHz Digital SWR/WATTmeter capable of displaying both the SWR and P.E.P.power values, with a bar graph on the second line tracking the instantaneous power.

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

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

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

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.

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.

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

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

A DDS VFO using the Arduino Uno platform

Easy circuit that provide good gain to weak audio signals

GNU Radio is a collection of software that when combined with minimal hardware, allows the construction of radios where the actual waveforms transmitted and received are defined by software

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.

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.

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

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

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

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

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

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 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.

Build a 5 watt, 80 meter QRP CW Transceiver Designed by N1HFX

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

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