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A25UK DXPedition to Botswana 25th April - 5th May 2017

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.

Description of an optimal backpack used for pedetrian mobile operation both on HF and VHF bands.

Since 1988, Royal Communications International has been supplying communications equipment designed for the military, professional, and amateur market. We specialize in the sale and service of High Frequency, Single Sideband transceivers that are dependable and easy to use.

SH6 is a versatile, browser-based utility designed for the detailed analysis and visualization of amateur radio contest logs. Supporting standard formats such as Cabrillo and ADIF, the tool allows operators to upload personal files via drag-and-drop or access a searchable public archive containing over one million logs. Key capabilities include comprehensive performance metrics, offering summaries of band breakdowns, QSO rates, and beam headings. Furthermore, SH6 provides advanced geographic visualization through interactive maps, analyzing contacts by country, zone, and continent. A standout feature is the side-by-side comparison mode, enabling users to contrast two distinct logs for strategic assessment. SH6 transforms raw log data into actionable insights regarding operator performance without requiring software installation.

Spotty leverages Philip Gladstone’s pskreporter.info data, delivered via an MQTT broker by Tom Fanning (M0LTE), to offer a responsive web application for visualizing propagation. The Map View presents a default visualization (grid AA00 / callsign MY8CALL) and distinguishes signal types: small spots for signals heard by a location, large spots for transmissions from a location, and teardrop markers for transmissions from the monitored callsign. Clicking a spot reveals detailed signal data in an overlay. The application includes a Log View for raw spot data and a Settings tab for customization. Users can filter tracking by specific Callsign or Grid, with preferences saved to the browser. A notable feature is the Time to Live (TTL) setting, adjustable from the default 60 seconds, which controls spot visibility duration to manage map clutter during high-traffic periods. The tool provides a clear, logic-driven interface for real-time signal monitoring.

The TangerineSDR is a Modular Software Defined Radio Project with the following objectives, Development of SDR radios that allow experimentation, provide support to unaffiliated other groups, to provide hardware modularity, to allow varying performance, To allow users to experiment with differing configurations.

Reviving the spirit of early ham radio experimentation, the CW Flea is a contemporary Morse code transmitter. Utilizing an Arduino Nano, Si5351 clock generator, and innovative design, this open-source project offers simplicity, flexibility, and easy tuning for aspiring radio enthusiasts.

HF contesting is a rising aspect of amateur radio that can be enjoyed (at any level) throughout the year. There are HF and LF contests almost every weekend and on some weekday evenings. Learn how to take part in HF contests.

An homebrew HF Magnetic loop made with 2m length of 6mm diameter copper pipe formed into a near circle as the low loss inductor, a short length of coax as a capacitor,a short length of mains cable, again as a fixed tuned capacitor, a tunable 365pF air spaced capacitor, and a small Jackson C804 airspaced variable with a small 3-35pF trimmer in parallel

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

A growing set of pages with tools and analyses of various elements of data elements based on Sherwood RX tests

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.

How to verify what Com Port you have on your computer running WIndows XP or Windows 7. Installing the Proper New Prolific PL-2303 Drivers and how to verify the prolific drivers are correctly installed.

VARA HF is a soundcard modem that can be found on the HF bands exchanging traffic (Winlink). VARA implements an High Speed Data Mode and comes in 2 separate programs VARA FM and VARA HF. VARA is a High Performance HF modem based on OFDM modulation. VARA Modem, brings state of the art Military grade technology to new and existing HF data. Introduces a new standard of technology available for Amateur and Commercial use. Designed for operation within a SSB Bandwidth of 2400 Hz.

This is a design based on the QuickYagi 4 software by WA7RAI with some changes for practical reasons. The beam uses 6.5 metres of standard 25mm square boom, 12mm diameter elements without tapers. The actual boom length used is 6.3 metres and all parts are readily available.

Helical antenna or helix antenna is the antenna in which the conducting wire is wound in helical shape and connected to the ground plate with a feeder line. It is the simplest antenna, which provides circularly polarized waves.

The resource details HF time broadcast stations, categorizing them into "Standard Frequency & Time Signal Broadcast" and "Time Signal Broadcast" types. Standard Frequency & Time Signal Broadcasts, like those on **2.5 MHz** and **5 MHz**, originate from official time observatories and offer continuous standard frequencies, time signals, and often voice announcements, potentially including meteorological data. These stations operate in the SW band. Time Signal Broadcasts also provide continuous time signals, typically with voice announcements, but without the strict observatory origin requirement. The list includes specific frequencies such as 3.33 MHz, 4.996 MHz, 7.85 MHz, 9.996 MHz, 14.67 MHz, 14.996 MHz, 15.006 MHz, and 20 MHz, alongside the primary standard frequencies. Each entry specifies the station's ID time, call sign, geographic coordinates, and operational notes, including languages like _English_, Chinese, Portuguese, Korean, and Spanish. Some entries also indicate decommissioning dates, such as the station on 3.33 MHz scheduled for 2026-06-22.

High Altitude Ballooning makes for a challenging project that sometimes turns into an engrossing hobby. Whilst it is not rocket science it does encompass a wide range of fields (sometimes literally) and there is a lot to learn before you send your first flight up into the sky.

CW Morse Nano QRP and Micro Keys. CW Morse PCB Keys. Morse Keyers

Constructing a 5-element quad antenna, the author aimed for low cost and simplicity, resulting in an effective design with 11 dBi gain and SWR of 2:1 or better across the 2-meter band. Using wood and dowels, the antenna costs under $8 and takes less than two hours to build with basic tools. The model predicts excellent performance, confirmed by ARRL Lab measurements. Practical field results demonstrate improved communication, even in simplex mode.

Check your RF power with an easy to read and build digital display

Amateur radio antenna manufacturer, HF VHF UHF antennas, and amateur radio accessories dealer based in Lingen Germany

This DIY guide details constructing a 5-element Yagi antenna for VHF frequencies. Yagi antennas offer directional signal transmission/reception compared to omnidirectional ones. The guide covers material selection (aluminum, screws, etc.), design using software or formulas, and step-by-step assembly including cutting elements, drilling holes, and attaching the coaxial cable. While calculations are provided for a 146 MHz design, adjustments are necessary for different frequencies. Safety precautions and potential result variations are emphasized.

Adjust date and time of your Icom transceiver from a Windows PC. Compatible with IC-705, IC-7100, IC-7300, IC-7610, IC-7600, IC-7851 (7850), and, IC-9700

A Beverage antenna system consisting of 4 time reversible Beverage antennas in length of 320m each.

The author presents initial NEC model results for a reversible 40-meter Moxon antenna, comparing three distinct designs: a standard rectangle, a _W6NL short-tipped_ variant, and a T-hat configuration. All three models exhibit similar electrical performance, with gain figures around **5.5 dBi** and front-to-back ratios exceeding 20 dB. The primary differentiation among the designs lies in their mechanical construction and physical dimensions, which are critical for a 40-meter antenna. The rectangular Moxon requires robust support due to its element lengths, while the T-hat design offers enhanced structural integrity with slightly longer elements. The T-hat model is provisionally selected for further development, emphasizing the importance of mechanical considerations over minor electrical performance differences. Future work will focus on detailed mechanical design and construction aspects of the chosen T-hat configuration.

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.

The CW typewriter is a compact adapter board that transforms Morse code into ASCII characters using an Iambic key. It connects to a computer via USB, emulating the keyboard. The device features inputs for Iambic keying and a WPM speed potentiometer, and outputs for a key and a speaker for side tone. The device can be used with various software and online typing games for practice, offering a unique and interactive way to learn and use Morse code.

Build your own 3-IC Iambic Electronic Keyer. Here, you will find schematics and operation descriptions. Includes Dot/Dash Memory, Progressive Element Weighting

An international team will activate amateur radio DXpedition station VK9WA from Willis Islets November 12-21, 2015

The author describes his experience building and using a Beverage antenna for the 40-meter band. Despite encountering some challenges, the antenna offered some improvements in receiving stations compared to a 3-element inverted Vee antenna. The Beverage antenna showed a significant daytime signal-to-noise ratio improvement and received signals better than the Vee antenna. However, the front-to-back ratio was not ideal, and the transmit power seemed to affect the Beverage antenna. Overall, the author concludes that the Beverage antenna might be more suitable for locations with higher noise levels. The total cost of the antenna was around 30 Euros.

Modifying the ICOM IC-756 Standard (non-Pro model) for 60m takes a little work, but it is worth the effort.

Homebrew a 9:1 transformer and measurement for testing purposes with a miniVNA

Data Decoder Utility is designed to enhance the operating experience for Flex Radio users by providing advanced connectivity to Peripheral equipment and radio control programs (RCPs) otherwise not available.

This guide explores the captivating hobby of shortwave listening (SWL), offering insights for beginners and enthusiasts alike. It covers key shortwave broadcast bands, essential tools like antennas and receivers, and practical tips to enhance listening experiences. Recommendations include budget-friendly SDR receivers, traditional radios like the TECSUN PL-680, and antennas suited for various environments. Additional resources, such as the World Radio & TV Handbook and online tools like Short-Wave.Info, are highlighted to help identify signals and maximize the enjoyment of SWL.

This innovative antenna tuning unit (ATU) enables QRP operators to match their antennas without transmitting RF signals. Using a noise bridge technique instead of traditional transmit-and-tune methods, it achieves truly silent operation. The design incorporates an L-match network with switched inductors and variable capacitor, handling impedance matching from 3-30MHz. Operating from a 9V battery, it includes a built-in RF power meter and dummy load for QRP transmitter testing. The compact unit is particularly suitable for portable operations where minimal RF emissions during tuning are desired.

Amateur radio SDR Receiver and Transceiver manufacturer , makers of the Silphase R1 an innovative HF receiver with high performance real-time spectrum scope.

This project outlines the construction of a simple TEFV (Tilted End-Fed Vertical) antenna suitable for backyard or park installations. The design requires basic materials such as 100 feet of coated stranded copper wire, wood stakes, metal ground rods, a non-conductive fiberglass pole, and essential tools like wire cutters and a soldering iron. The antenna is supported by a 20-33 feet tall pole and includes a 9:1 unun for impedance matching and a resistor for tuning. Step-by-step instructions guide the assembly, from preparing the wire and pole to connecting the unun and resistor, ensuring a functional and durable setup for outdoor use.

Ferrite E-cores offer a practical solution for constructing baluns, especially when connectors are already mounted on cables. These cores, commonly used in mass-produced pulse transformers, allow for multiple turns without dismounting connectors, making them ideal for control and power supply cables. The material of E-cores is generally suitable for common mode baluns up to 15 MHz, providing a cost-effective option for amateur radio operators. E-cores can often be sourced from old switch-mode power supplies, adding to their appeal for those looking to utilize existing resources. A notable example involves a balun on a USB cable using a Ferroxcube E 32x16x9, 3F3 core with four turns, secured by three cable ties. This setup demonstrates the ease of construction and stability achievable with E-cores. Another example features a balun with eight turns of shielded cable with RCA connectors on the same core, achieving 140 uH inductance at low frequencies. The impedance plot for this configuration is measured between the shield ends, illustrating the effectiveness of E-cores in practical applications. The article includes detailed figures and descriptions, providing valuable insights into the construction and application of baluns using ferrite E-cores. These examples serve as a guide for amateur radio enthusiasts looking to enhance their setups with cost-effective and efficient solutions.

This study details a reception comparison between vertical and horizontal active loop antennas, specifically two identical _Wellgood active loop antennas_, on various HF bands. The experiment, conducted in a densely populated QRM-prone area, monitored FT8 signals over a 24-hour period using two identical receivers. The methodology involved direct comparison of signal reception across the HF spectrum, aiming to identify performance differences based on antenna orientation. The results indicate that vertical loops demonstrated superior performance on higher bands (10m, 15m, 20m), while horizontal loops excelled on lower bands (30m, 40m, 160m), particularly for receiving long-distance (DX) signals. The horizontal loop's advantage on lower bands is attributed to potentially better low-angle performance and reduced sensitivity to man-made noise, yielding a **2-3 S-unit** improvement on 160m. The study provides practical insights for optimizing antenna placement in challenging urban environments, noting that the horizontal loop consistently showed a **10-15 dB** signal-to-noise ratio improvement on lower bands.

Power Solutions for Durable Communication Systems. Founded in Sep. 1992, DuraComm Power Supplies is a worldwide recognized leader in ultra-reliable AC-to-DC switch mode power supplies commonly used in the communications industry.

Saluki manufacturer of Spectrum Analyzer, Handheld Spectrum Analyzer, Signal Analyzer, Cable and antenna analyzer, Network Analyzer|RF Signal Generator, Cable Antenna Analyzer

EA4EOZ details the construction and testing of 50 MHz traps, a critical component for multiband antenna designs. The project addresses the challenge of sourcing high-voltage capacitors suitable for trap applications, exploring alternatives to expensive doorknob capacitors. The author successfully fabricated a capacitor using 1.6mm double-sided FR-4 PCB material, achieving a capacitance density of **2.6 pF/cm2**. Utilizing the _VE6YP calculator_, specific L and C values of 30 pF and 0.31 uH were determined for a 2cm diameter coil. Both the FR-4 PCB trap and a coaxial cable trap, constructed from _RG-58_, were built and tuned to approximately 50 MHz using a spectrum analyzer. The coaxial cable trap demonstrated superior performance, exhibiting a notch nearly **20dB deeper** than the FR-4 version. This practical comparison provides insights into trap construction for experimental antennas, with the coaxial cable trap selected for an antenna project intended for operation at up to 100 watts.

Over 15 amateur radio bands, from 160m to 70cm, are supported by the _DXTRON_ web cluster, providing real-time DX spotting information. This service integrates directly with the _QRZCQ_ API, allowing users to monitor activity across various modes including CW, Phone, Digi, RTTY, SSTV, and SAT. DXTRON displays critical spot data such as timestamp, spotter callsign, frequency, mode, DX call, and remarks, along with geographical details like Grid, DXCC, ITU, CQ zone, continent, and country. Developed by _DO5SSB_, DXTRON v1.42 offers a user-friendly interface for filtering spots by band and mode, catering to both casual DXers and serious contesters. The platform is designed for accessibility, providing a clear overview of current propagation conditions and active stations worldwide. This web cluster is a practical tool for hams seeking to identify rare DX, track contest activity, or simply observe band conditions. Its reliance on the QRZCQ API ensures a consistent flow of up-to-date spotting data, making it a reliable resource for real-time operational awareness.

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.

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.

Featuring Grant County WI Scanner and Jo Daviess County IL Scanner. DDUBUQUE, Iowa

XR0ZRC DX Pedition to Robinson Crusoe Island 2019 IOTA SA-005 Juab Fernandez Islands 14 March - 3 April 2019

There are many feed systems used in yagis over the years. Gamma matches are not as common as they once were. More typical are beta matches and T matches to convert the low impedance of a yagi to 50 ohm.