Search results

DXPSK and SMARTPSK are freeware Windows PSK31 software tools capable to send and recive even multiple tracks of PSK31 signals. SMARTPSK is the improved version of DXPSK capable to display up to 25 tracks.

The SM1000 allows you to run FreeDV without a PC. Connect the SM1000 to your SSB radio, and you now have Digital Voice (DV). You don’t have to buy a new radio to run Digital Voice! It’s based on a STM32F4 micro-controller, has a built in microphone, speaker amplifier, speaker, and transformer isolated interfaces to your radio.

The title may seem a strange question. Still, it is often said that the part where the current is largest, radiates most. And from that a rule of thumb follows, saying that if you don't have enough space to hang a complete half-wave wire dipole then try to make the central part hang as freely as possible.

_Amphenol RF_ manufactures RF connectors, RF adapters, RF attenuators, RF cable assemblies, and RF terminators. The company offers custom RF solutions, including modified connectors and integrated cable assemblies. Product examples include SMP to SMPM adapters, surface-mount SMB jack connectors, end-launch SMA bulkhead connectors, and non-magnetic SMPM connectors. The company's product portfolio also features single-crimp N-Type connectors, USCAR compliant Mini-FAKRA connectors, 2.4 mm to 2.4 mm adapters, and 2.92 mm plugs for 0.141-inch cable. _Amphenol RF_ produces MMCX and MCX cable assemblies on RG-316 and RG-174 cable, PFAS-free SMA connectors, and FAKRA rear mount bulkhead plugs for RG-58 and LMR-195 cable. Additional offerings include 2.92 mm to 2.92 mm adapters, BNC bulkhead jacks, SMA to MHF 4 LK cable assemblies, and 2.92 mm to SMA adapters. _Amphenol RF_ is headquartered in Danbury, Connecticut, and operates as part of _Amphenol Corporation_. The company maintains a global manufacturing and distribution network. DXZone Focus: RF connectors | Cable assemblies | Danbury, Connecticut | _Amphenol Corporation_

DXSPOTS is a Telnet connection program. It allows radio amateurs with a lot of DX traffic to know instantly the status of the bands and to know which DX are currently on the air. Following the Packet-Clusters where data was transmitted on VHF/UHF via dedicated relays and sometimes on HF at a very low speed (300Bds on HF), the Internet has taken over and is now transmitting DX information via the computers in most shacks. Translated with www.DeepL.com/Translator (free version)

Free windows application for RF Microwave and Wireless applications. AppCAD is useful for the design and analysis of many circuits, signals, and systems using products from discrete transistors and diodes to Silicon and GaAs integrated circuits. AppCad is a unique suite of RF design tools and computerized Application Notes to make your wireless design job faster and easier

FreePCB is a free, open-source PCB editor for Microsoft Windows, released under the GNU General Public License. It was designed to be easy to learn and easy to use, yet capable of professional-quality work.

By F2JD as HR5/F2JD from Copan Ruinas Honduras

Dipole for 40m band. It is a simple linear loaded dipole feeded with 450-Ohm openwire feedline. Designed it for resonance at 7.050 MHz, can be tuned on 30m and 80m bands with an external antenna tuner. Build with simple electrical copper wire (2.5 mmq/13 awg) and two fishing poles with size of about 7 m/23 ft.

Ham racio clip art collection with free to use images. Additional amateur radio clip art can be found by changing the search term

SmallDV is an embedded FreeDV for Raspberry Pi from Matt KK5JY

CW_Player is a freeware Morse code training program designed for aspiring and experienced radio amateurs. It generates Morse characters, Q codes, abbreviations, and random text, offering 20 customizable lessons for learning Morse code. The software includes a quiz for knowledge testing, CW signal monitoring to decode morse code live, and the ability to create personalized local characters. It generates .wav files for playback, supports Windows features like copy-paste, and integrates easily with transceivers for on-air training. Ideal for beginners, instructors, and hobbyists, CW_Player boosts confidence in CW operations.

A collection of ham radio clip art royalty free. Additional amateur radio clip art can be found changing the search terms.

The Saturn PCB Toolkit is the best freeware resource for PCB-related calculations you can find. It incorporates many features that PCB designers and engineers are in regular need of like current capacity of a PCB trace, via current, differential pairs and much more. Please download our PCB Toolkit today for free and enjoy!

MLog 0.8d is a freeware logging software designed for Windows operating systems (NT, 98, ME, 2000, XP) that facilitates the logging, management, and analysis of amateur radio QSOs. It features a customizable input mask for rapid contest logging, a robust search function for existing contacts, and immediate data storage in CSV format to prevent data loss. The software also includes a double-check mechanism against reference logs during callsign entry, integrated DXCC information, and a "magic field" for streamlined data input, all within a single-window interface. Key functionalities include graphical QSL card management via _QSL-Collection_, CW output through soundcard or PC speaker, and direct access to _Radio Amateur Callbook_ data. MLog supports transceiver control via _Ham Radio Deluxe_ URLs, offers a detailed world map with locator conversions, and can launch _VOACAP_ through _HamCap_. It provides extensive data analysis options for QSLs, _Locator_ large fields, _DOKs_, _DXCCs_, QSO counts, and user-defined contest evaluations, alongside flexible import/export capabilities for various log formats.

The Raspberry PI 3+4 has proven itself as an amateur radio computer. Both at home as the main computer in the shack but also on the road. It is small, inexpensive and incredibly versatile. The operating system and the most important programs are available for free.

This is very common W7IUV Flag Antenna design is based on the PY3AGD antenna because it uses the antenna mounted horizontally and nd it is perfect for my small city lot installation.

ToyNTP is a simple freeware time server for Windows that implements the SNTP protocol and uses a GPS receiver, Garmin GPS 18x LVC, as time reference. ToyNTP was designed to be used with Faros in the locations where access to the SNTP servers on the Internet is not available, but it may be used for other purposes as well, in particular, it may be configured to keep the PC clock synchronized to a GPS receiver.

How to setup and work SO2R with N1MM the popular free contest logging software

A simple DIY project for a remote cw key connected to your Flex Rig (actually it can be any other rig). On the remote side it uses and Arduino Uno board and a cheap HanRun Enc28J60 ethernet shield. On the local side it uses a key (better a keyer) connected to a serial port of your pc

A comprehensive and exhaustive review of Yaesu FTDX101 transceiver. Article is in Italian and can be easily translated in your language

SNASharp is a free software application designed to work with scalar network analyzers compatible with NWT software from DL4JAL. It is used to measure and analyze the scattering parameters (S-parameters) of microwave devices. Provide several measurements and analysis tools including Smith chart, Polar plot, S-parameter tables, Transmission line calculator

Signal Stuff operates as an online retail outlet specializing in amateur radio antennas and related accessories, with a core mission to financially support educational platforms like HamStudy.org and ExamTools.org. The product line prominently features their Super-Elastic Signal Stick™ antennas, available with SMA-F, SMA-M, and BNC connectors, designed for various handheld transceivers including Baofeng, Icom, Yaesu, and Kenwood models. The site details product specifications, pricing, and a lifetime warranty for the Signal Stick™ antennas, emphasizing their role in funding free ham radio licensing study guides and exam administration software. Proceeds from antenna sales directly contribute to the development and maintenance of HamStudy.org, a free online resource for amateur radio license preparation, and ExamTools.org, software utilized by Volunteer Examiner (VE) teams for efficient exam administration. The site also promotes HamBook.org, a free series of comprehensive study guides, which integrates with the HamStudy app and website through links and QR codes for an adaptive learning experience. This business model links product sales to community support, providing essential tools for aspiring and upgrading amateur radio operators.

Free PDF book to start learning morse code and to improve your proficiency, freely available in four languages english, german french and italian.

Filter Free is the shareware version of Filter Solutions and Filter Light. Filter Free is limited to 3rd order or lower low and high pass filters, 2nd order or lower band pass and band stop filters, and 10 tap or lower FIR filters, and does not include most of the advanced design capabilities of Filter Solutions and Filter Light.

AZIWORLD is a user-friendly tool for generating azimuthal maps of the Earth centered on any location. Compatible with Windows XP and later, it supports English and French. Maps can be saved in .bmp format for easy customization. AZIWORLD computes azimuths, distances, and geographical positions, integrating seamlessly with AZIPOINT for automatic antenna pointing. Linux/Ubuntu/Android users can run AZIWORLD via WINE or CROSSOVER. For optimal functionality, installing AZIPOINT alongside AZIWORLD is recommended.

Controlling a rotator via computer can be costly, but a budget-friendly solution exists using an Arduino Nano and free software by Anthony K3NG. This setup allows for easy and enhanced rotator control, including screen and network management. Though initial software setup can be complex, pre-configured versions are available. Building and customizing the hardware interface is required, with comprehensive support provided by K3NG's resources.

TFilter is a free online tool for designing linear phase, optimal, equiripple finite impulse response (FIR) digital filters. It utilizes the Parks-McClellan algorithm implemented in JavaScript. Users can specify the sampling frequency, desired number of taps, passbands, and stopbands to generate a filter. An example configuration is provided for easy testing.

Arduino Flex Controller can be used with the new Flex 6000 Signature rigs. It is a DIY project and in these pages you will find all the informations you need to build and program your own. It is a perfect companion when used next to the official SmartSDR program but it can be used in stand-alone mode, without a PC.

Presents an interactive online **Moxon antenna designer** tool, enabling radio amateurs to configure and analyze lightweight Moxon antennas for HF and VHF bands. Users can specify design frequency, element lengths, wire diameter, insulation, and support height. The tool visualizes the antenna in interactive 3D graphics and generates comprehensive performance charts, including azimuth, elevation, 3D, and polarization radiation patterns, VSWR charts, antenna current diagrams, and Smith charts. It also allows selection of various ground types (e.g., very poor soil, salt water, free space) to model environmental effects on antenna performance. The designer provides insights into how physical dimensions and ground conditions influence key antenna parameters like forward gain, front-to-back ratio, and feed-point impedance, which is typically close to 50 ohms. It also includes a feature to model the effect of coaxial cable losses on **VSWR** at the transmitter end, distinguishing it from the feed-point VSWR. This helps operators understand the actual radiated power efficiency versus the apparent match at the transceiver, offering a practical perspective on antenna system performance in portable operations.

The article describes the construction of a Lindenblad antenna, which is well-suited for receiving signals from low-orbiting weather satellites. The key points are: The Lindenblad antenna has an omnidirectional horizontal radiation pattern and is optimized for low to medium elevation angles, making it ideal for tracking passing satellites near the horizon. It is designed to receive circular polarization, which is common for weather satellite signals. The antenna is constructed using 4 folded dipole elements arranged on a cross-shaped frame. The necessary materials include a plastic junction box, PVC tubing, and aluminum rods to form the dipole elements. The article provides detailed instructions for preparing the components, assembling the dipoles, and connecting the feed lines to create the complete antenna. The completed antenna can be mounted on a vertical support, with the dipole elements angled at 30 degrees from horizontal, to optimize reception of the passing satellites. The author notes that the design was originally published in a now-defunct magazine, Meteo Satellite Inf", in 1993

KB3IFH Full Color quality QSL & Eyeball cards. Free custom design & imaging scanning, based in Hampstead, MD USA

VarAC is a FREE, modern HF P2P real-time chatting application for the amateur radio operator that leverages the glorious VARA protocol

The WesseX Repeater Group GB3WX - GB3WSX - GB3YS

HFN (Hands Free Nanokeyer) is a 3D Printer made morse keyer. In this project the athor shares the STL printer model files for the 3 versions build.

A homebrew spectrum analyzer, the Specan, provides a crucial measurement capability often missing from the typical amateur radio shack, allowing for detailed analysis of RF signals up to 70 MHz. This double-conversion superheterodyne receiver design incorporates 112 MHz and 12 MHz intermediate frequencies, utilizing an _Si570_ as the local oscillator for fine tuning down to 1 Hz steps. It offers two resolution bandwidths: 300 KHz for broad spectrum sweeps and 1 KHz for precise close-in distortion measurements, achieving an 80 dB spur-free dynamic range at 1 KHz resolution. The project, a reboot of the classic _W7ZOI/K7TAU_ design from November 1998 QST, integrates an _Arduino_ microcontroller for controlling the Si570, managing a front-panel LCD, and communicating with a PC for spectrum plotting. This approach significantly reduces cost compared to commercial units, making advanced RF diagnostics accessible to homebrewers. The Specan can measure carrier suppression, VFO cleanliness, antenna VSWR, transmitter harmonics, and filter passband shapes, providing insights beyond what an oscilloscope or frequency counter can offer. Construction emphasizes modularity and careful shielding, with each stage built and tested individually on unetched copper clad board. The design includes detailed instructions for integrating the Arduino, building the Si570 oscillator, and aligning the various modules, often using the Specan itself for calibration. It requires a well-regulated linear power supply and can be built with common tools and readily available components, making it a practical and rewarding endeavor for those looking to enhance their RF test bench.

A portable QRP setup based on 20/30/40m QRP CW-only SW-3B transceiver, 2500mAh 5C LiPo battery (147g), Hands Free Nanokeyer

flcluster is a free multiplatform dx cluster client that connects to and displays data from DX cluster servers. The three most common server types are AR-Cluster, CC-Cluster, and DX Spider. The program is designed to work stand alone or as a helper application to fldigi. It can transfer call, mode, and frequency data from a spotted QSO to the appropriate fldigi controls. It can query fldigi for the same items when generating a spot report.

Online phonebook of Hams Over IP. List of all registered HoIP Extensions, but even active BLK, Conferences, and allstar Links. HoIP is a free VoIP service for hams.

SW Keyer for remote operations. This is a simple tool based on the Morse Code Iambic and Semi-Automatic Keyer from the Morse-Code-Tools projects. You can use your key, bug or Iambic Paddle stright connected to your personal computer without a hardware morse keyer.

A vertical delta loop is a practical antenna for low bands, popular for its simple design requiring just one support. Its shape, an equilateral triangle in free space, yields optimal gain and radiation resistance. Deviating from this shape lowers performance. The delta loop can be polarized either horizontally or vertically based on the feed point location. In vertical polarization, it acts as two quarter-wave verticals with the baseline feeding one side. This design minimizes radiation from the baseline while maintaining effective operation.

A free web app that converts ADIF files into KML format for viewing on Google Earth or other KML viewers. Users can view QSOs on a 3D globe, click on station markers for details, and navigate the globe. The page provides instructions, features, limitations, and requirements for using the tool.

Inverted L antenna, even if not completely freestanding, it only requires one line to be lauched into a tree to support the end of the horizontal wire. This project is done with a 31-foot Jackite pole for a support and uses six 15-foot radials and one 33-foot radial.

UR6QW offers special devices for ham radio operators, including PCBs and complete constructions in metal housing. Audio Equalizer, Echo boards, Metal stands. They provide pinouts for many transceiver models and can accommodate special orders upon request. The website also mentions the availability of sending parcels via DHL from their German office for European countries. Visit UR6QW for detailed information and sign up for free now.

FreeDV uses an audio codec as a software based modem to decode and encode the voice and text data from your computer. The data is encoded and then is transmitted over the HF radio using AF signals that can then in turn be decoded by the receiving station.

The 8m ISM band, a unique frequency range between 10m and 6m, holds potential for amateur radio enthusiasts, yet it remains largely unallocated. This spectrum offers fertile ground for research and self-training. The author's experience with low-power transmissions and WSPR testing highlights the band's capabilities and the need for a narrow, speech-free amateur allocation to encourage experimentation. Discover the world of 8m ISM radio exploration and its future possibilities.

Many low-power SSB rigs and kits lack dedicated speech processor circuitry, although most modern HF rigs include it. Speech processing is crucial for low-power SSB to overcome QRM. This simple, low-cost circuit integrates a microphone element and can be housed in a defunct desk mike. It features a feedback amplifier, audio preamplifier, and adjustable speech compression control

This amateur radio website explains how to use the free AGWPE utility program to send and receive packet data using the sound card of your PC. Note that AGWPE is a Windows-only program. This website, which is hosted on SV2AGW's web site, focuses on support for the sound card packet features of AGWPE.

The XX9D Log Online provides a direct log search function for the DXpedition to Macao, specifically detailing operations conducted in 2017 and 2019. This service allows amateur radio operators to verify their contacts (QSOs) with XX9D, a critical step for QSL card management and award applications. Users are explicitly advised to consult the online log to prevent duplicate contacts on the same band and mode, optimizing efficiency during active DXpedition periods. This online tool supports the "DX Code Of Conduct," promoting ethical operating practices within the amateur radio community. The platform facilitates the Online QSL Request System (OQRS), streamlining the process for requesting QSL cards without the need for traditional bureau or direct mail methods. Operators are instructed to defer OQRS submissions until the conclusion of the DXpedition, ensuring all logs are finalized. The log search interface is powered by CMSimple, a content management system, indicating a straightforward, database-free web application. The resource is designed for ease of access, providing a clear method for DXers to confirm their contacts and manage QSL requests efficiently.

A Case For Thunderstorms Causing Sporadic E on 6 Meters. In Propagation and Radio Science, Eric Nichols explains one possible mechanism is thunderstorms that are strong enough to break electrons free forming a cloud of free electrons.