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winding coils for construction project

LinLogBook is an logbook for hamradio and it is based on an sql database. It can be widely configured by the user.

Audacity is a free, easy-to-use, multi-track audio editor and recorder for Windows, Mac OS X, GNU/Linux and other operating systems. The interface is translated into many languages.

The N3UJJ antenna project,parallel-cage dipole a multi-band horizontal antenna, without the need of an antenna tuner.

Demonstrates the construction and tuning of a **20-17-15 meter fan dipole** using 12-gauge PVC insulated copper wire and an Alpha-Delta C kit feedpoint. The project details the use of 14-inch pine dowels with 6-inch spaced holes to maintain wire separation for the parallel elements. Initial tuning was performed at shoulder height, with final adjustments made after elevation to 38 feet, accounting for frequency shifts observed between ground-level and elevated antenna positions. SWR analysis graphs are presented, showing performance below 1:3 across the entire 20-meter band, below 1:2 for 17 meters, and below 1:3 for 15 meters. The author notes significant RX improvements of +3 to +9 dB, occasionally exceeding +20 dB, compared to a commercial Alpha Delta DX LB Plus. The total hardware cost for this DIY antenna project was approximately $90, with the author emphasizing the utility of an **antenna analyzer** like the RigExpert AA54 for precise tuning. The fan dipole also exhibits tunable resonance on 12, 10, and 6 meters, though with reduced efficiency. Performance comparisons on 20 meters showed the fan dipole outperforming the Alpha-Delta on long-path north-south DX contacts.

A CB to six meter transverter project by ZS2ACP

Allow the reception of amateur signals on domestic AM-only short wave receivers article and project by VK3YE

80 metre superhet SSB receiver project

Hone your Morse code skills with this entry-level project. Article includes the full schematic of the CW Trainer, describes the sketch and how to operate the morse code trainer.

Simple 6 Metre DX Antenna based on an article by LB Cebick in QST May 2002 on a Quad Turnstile antenna. This antenna is basically two full wave loops mounted at right angles fed 90 degrees out of phase to produce an omni-directional horizontally polarized pattern

This project was intended to accompany the stealth antenna project. Author want to see how effective a noise canceller could be in reducing the background noise floor when attic / stealth antennas are being used.

N3OX three meters Flex Vertical, a Short, Frequency Agile Vertical for 40 meters

Collection of Kenwood TL-922 linear amplifier modifications

A project with schematic to build a receiver for 80 meters band by VK1PK

A collection of modifications and improvements to the Ameritron ALS-600 ham radio RF power amplifier

Project Condor16 VHF transceiver

The idea makes use of a very simple direct conversion receiver on the band of interest.

A moxon antenna project by KD6WD

This transmitter was first constructed in 1987 and provided the author with his first real rig, capable of distances of more than about 100 metres.Use a 6GV8 tube.

FLMSG is a simple forms management editor for the amateur radio supported standard message formats. Form data can be transferred between computers either using standard internet email or via radio frequency broadcasts typically made by an amateur radio operator on your behalf.

This project is based around the recent HF1 QRP transceiver by Ashhar Farhan, VU2ESE. The transceiver is an interesting SSB design with wide tuning range from 0-30MHz and should cover several amateur bands. The schematic for the transceiver can be found on the Minima mail list in this post with a PDF attachment

Make and automatic antenna tuner based on Arduino and using economic card. This ATU Project can be installed outdoors and controlled remotely by an rs485 link

Modify a KPC-9612 to give a total of four analog input for remote monitoring and telemetry.

DragonOS is a linux distribution dedicate to Software Defined Radio. It leverages the portability, security, and power of Lubuntu Linux as a delivery package and operating environment for a pre-installed suite of the most powerful and accessible open source SDR software. DragonOS has verified support for a range of inexpensive and powerful SDR hardware, including RTL-SDR, HackRF One, LimeSDR, BladeRF, and many others.

Variable Power Supply for the bench

A battery voltage booster project with pictures and schematic by KD7W

AX.25 Packet Modem homebrew project on Arduino

This converter uses the popular NE602 mixer/oscillator chip and allows reception of signals below 500 kHz on a 3.5 – 4 MHz HF receiver

An HF vertical antenna by N3OX with a flexible capacitance hat

The Microsniffer is a fully autoranging VHF or UHF sniffer which has been designed for those who are foxhunting on a budget.

Two find dipoles one for 75/40/20 and the other for 20/15. These 2 dipoles are at right angles to each other and the 20/15 dipole is located about 6 feet below the 75/40/20 fan dipole.

Heathkit SB220 refurbishing by PA5CA

The CSV19 is an homemade antenna launcher project. In this article you can find pictures, drawing, and material list

This code practice oscillator project uses a 555 timer IC. Includes a Schematic Diagram of the morse code oscillator

Constructing a compact directional antenna for the 17-meter band, this resource details the build process for a Moxon rectangle, a two-element Yagi variant with folded-back elements. It covers the antenna's evolution from the _VK2ABQ beam_ and provides specific dimensions for a version built using fishing pole whips. The content includes a discussion of the antenna's radiation pattern, feedpoint impedance, and its inherent front-to-back ratio, which is often superior to a standard two-element Yagi. Practical considerations for element spacing and material choices are also addressed, alongside a visual representation of the antenna's physical layout. Performance data presented includes a comparison showing the Moxon rectangle's **2.5 dB gain** over a half-wave dipole and a front-to-back ratio of **20 dB**. The resource also touches upon the antenna's relatively wide bandwidth for a two-element beam and its suitability for portable operations due to its compact footprint. It offers insights into optimizing the design for specific operating conditions and discusses the advantages of its lower take-off angle compared to omnidirectional wire antennas, making it effective for DX contacts on the 17-meter band.

Some modifications for the Tigertronics Signalink USB sound card radio interface

The document explains the technical aspects of how the Internet Radio Linking Project (IRLP) works, focusing on the use of VoIP streaming software under the Linux operating system. It details the audio sampling, compression, transmission, reception, and playback processes involved in IRLP communication.

Elecraft K3 vs. ICOM IC-781 vs. Kenwood TS-850: comparative Measurements and Experience

The SETI League, Inc., founded in 1994, focused on participatory science, developing technology to seek definitive answers to the question of extraterrestrial intelligence. The organization operated in five dozen countries across all seven continents, maintaining the quest for cosmic companions through the efforts of its 1500 members. Although the organization shuttered its virtual doors after thirty years in 2024, the website remains for educational and historical purposes, documenting past research and activities. Key technical resources include the _SETI League Mini-Manual_ for constructing a 12 GHz radio telescope under $200, and software like _SETIFox for Windows_ and _Radio Eyes_ for radio astronomy sky viewing. The site also features _Project Argus_ detections, moonbounce signal detections, and space probe signal detections, providing concrete examples of amateur radio astronomy applications. Publications such as the quarterly newsletter _SearchLites_ and various articles by Dr. SETI (H. Paul Shuch, Ph.D.) are available, alongside information on the Third Penn State SETI Symposium in 2025. The site also offers insights into hydrogen line emission observations, presented in time domain, frequency domain, waterfall, and surface plot formats.

A 70 MHz QRP transverter project

L4B by Drake amplifier mod

A project for a Moxon antenna for 7 MHz with pictures and EZNEC model

This is a description of how KO4BB built his tower. It is provided in the hope that it will be useful to anyone want to setup his own ham radio tower.

Build this noise reducing system to enhance audio of your speaker. A project by kg4jjh

A Linux Smith charting program. You can enter either discrete components or transmission lines, see the results on screen and/or generate Postscript output. Component values can be changed numerically or using scrollbar

This article was first published in CQ-TV issue 208. Author try to explain digital television in layman's terms and without getting too involved in mathematics.

Christoph Petermann DF9CY DRM demonstration receiver project including Circuit Diagram and component list

This circuit is very simple and has a fantastic range of potential uses.

Collection of ATV projects

A synthesized 2.3 GHz Amateur Television (ATV) transmitter design, conceived by Ian G6TVJ, is presented, targeting broadcast-quality video performance on the 13cm band and extending up to 2.6 GHz. The core of the design utilizes a commercial Z-comm Voltage Controlled Oscillator (VCO) that tunes from 2.2-2.7 GHz, providing a +10 dBm output and simplifying RF alignment. This VCO's stability, originally intended for narrowband applications, readily accepts high-frequency video modulation, contributing to the transmitter's robust performance. The exciter stage, incorporating a Mini Circuits VNA 25 MMIC amplifier, boosts the signal to +16dBm, while a Plessey SP4982 prescaler divides the output frequency for the synthesizer. The synthesizer employs a Motorola MC145151 CMOS parallel IC, favored over the common Plessey SP5060 for its superior video modulation characteristics and ease of programming without microprocessors. This choice addresses issues like LF tilt and distorted field syncs often seen with SP5060 designs, particularly when operating through repeaters or over long distances. The MC145151 divides the signal further, enabling precise frequency stepping, with programming handled by EPROMs for channel selection and LED display. The loop filter network, critical for video integrity, was developed through experimentation to prevent the PLL from reacting to video modulation, ensuring a clean transmitted picture. The transmitter incorporates a Down East Microwave commercial power amplifier module, delivering approximately 1.6W output, driven by the exciter through a 3dB attenuator. Construction involves surface-mount SHF components on micro-strip lines etched onto double-sided fiberglass board, housed within a tinplate box. The design boasts no AC coupling in the video path, preserving low-frequency response, a common failing in other ATV transmitters. Performance tests with a 50Hz square wave revealed no LF distortion, and a calibrated "Pulse & Bar" signal showed a near 100% HF response, demonstrating its capability for high-quality ATV transmissions.