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Program that produces antenna radiation patterns and graphs for SWR, forward gain, and F/B ratios

Online calculator for Bi-Quad antennas

The **NW3Z** optimized wideband antenna designs, originally presented at Dayton 2001, detail Yagi configurations for the 20-meter, 15-meter, and 10-meter amateur radio bands. This resource provides access to the design files, likely containing critical parameters such as element spacing, element lengths, and boom dimensions, which are essential for replicating these directional antennas. The designs focus on achieving wide bandwidth, a desirable characteristic for contesters and DXers operating across a significant portion of each band. The content specifically references "nw3z-Antenna-DesignsDownload," indicating that the core information is available as a downloadable file, presumably in a format suitable for antenna modeling software or direct construction. Such files typically include **NEC models** or similar data, allowing for performance analysis and optimization before physical construction. The emphasis on "optimized wideband" suggests design considerations for SWR bandwidth and gain characteristics over a broader frequency range than typical narrow-band Yagis. The resource serves as a direct source for specific, proven antenna designs from a known amateur radio antenna designer, offering practical data for hams interested in building high-performance Yagi arrays for HF.

Quagi antenna design, this little windows application let you calculate dimensions of elements and spacing of a quagi antenna. Freeware by VE3SQB

On-line single-layer coil designer

This page lets you do calculations for single layer air cored coils using the solenoid formula

We offer a large selection of standard and custom High Power RF and Microwave amplifiers for broadband, general communication, matched band, and personal communication markets.

DAVIS RF Co. has been in the business of supplying the staples of wire antennas for over 30 years. DAVIS RF Co. supply all coax cables, all connectors, ladder line, rotar control cable, insulators, and we have the largest selection of wire for wire antennas. DAVIS RF Co. is the designer and trade mark holder, and primary source for Bury-Flex Tm low loss coax cable. PolyStealth Tm high strength PE insulated antenna wire, and Flex-Weave Tm wire

Online helix antenna designer, calculate size of helix antennas online

International Components Corporation has an extensive range of electronic components consisting of audible signal devices, speakers, microphones, capacitors, electron tubes, connectors, and accessories designed in recognition of the diversity of applications and special characteristics encountered by designers in today's complex world.

Designers and manufacturers of radio Frequency antennas. HF - 3000 MHz TET Emtron HF Yagis, Antennas for Wireless applications, Marine antennas, Land mobile, Mobile antennas.

Resistor Finder is a program that allows the electronics designer or hobbyist to find a combination of 2 resistors that, when connected in parallel, will provide the best match to a desired resistance.

A danish only scale diagrams designer, usefull to draw front panels and dial scale knobs, windows freeware.

Front Panel designer by panel pool

Fill out the form to design a bandpass filter as described in the January 1985 issue of Ham Radio Magazine. These filters are generally limited to frequencies above 200 MHZ because their size is slightly longer than 1/4 wavelength

This page presents a curated list of individuals who have made significant contributions across various fields while also being active amateur radio operators. For instance, Dr. Joseph H. Taylor, co-winner of the 1993 Nobel Prize in Physics for the discovery of binary pulsars, is recognized for developing the _WSPR_ and _WSJT_ weak signal mode software. Similarly, Wilson Greatbatch, inventor of the cardiac pacemaker with over **150 patents**, is featured. The resource details the diverse backgrounds of these hams, from Professor Donald H. Menzel, an astrophysicist at Harvard, to Hiram Percy Maxim, often called "The Father of Amateur Radio," who also pioneered in the automobile and aviation industries. King Hussein of Jordan, JY1, is noted for his active participation on 20 meters, engaging with fellow amateurs like Pat Kilroy, WD8LAQ. Other entries include Arthur M. Young, designer of Bell Helicopter's first model, and Marlon Brando, KE6PZH/FO5GJ, known for operating from his private island in French Polynesia. Peggy Sue Gerron-Rackham, K5PSG, gained her license after a special event station, demonstrating the hobby's broad appeal.

G/T (Gain-to-Noise Temperature) is a critical figure of merit for evaluating the receive performance of VHF/UHF antennas, particularly for weak-signal work like EME (Earth-Moon-Earth) or meteor scatter. This resource presents extensive simulation data for numerous 2-meter and 6-meter Yagi antenna designs, originally compiled by _VE7BQH_ (Lance Johnson). The lists, updated as of October 2017, include various antenna models from designers such as _DK7ZB_, G0KSC, and K1FO, providing key performance parameters. Each entry details the antenna's G/T value, gain, front-to-back ratio, beamwidth, and VSWR at specific frequencies like 144.1 MHz or 145.0 MHz. The data facilitates comparison of different Yagi configurations, including those with folded dipoles and varying intrinsic impedances, aiding radio amateurs in selecting optimal antennas for their specific operational needs on the 2-meter and 6-meter bands.

Online calculator, Butterworth Bandstop (Notch) Filter Designer

Javascript filter design page with introduction to low pass filters by k7mem

Designer and manufacture of Airborne Antenna & Radomes covering a range of applications. Products include vhf antenna ,uhf antenna,navigation antenna,comm antenna,blade antenna,vor/ils antenna ,L band antenna, direction finding antenna,DF antenna,vor,ils, IFF antenna on aircraft,aircraft antenna for airborne application.

Designer and supplier of tower reinforcement systems to the wireless industry.

Butterworth Highpass Filter Designer

An online multiple calculator of 16 impedance matching networks

Custom Designed Photo QSL Cards, Full Color stunning designs, High Quality Printing at competitive Prices. US based QSL designer and printer specialized in custom-designed ham QSL cards.

Designer and manufacturer of RF amplifiers used in a variety of custom applications in many diverse industries - from Scientific, Medical, Industrial, and Communications and Broadcast.

JPR Electronics have been in the business of supplying electronic components and accessories to manufacturers, sub-contractors, designers, distributors, MOD, government departments and educational establishments

Calculate inductance online, with the cylindrical Coil Inductor Design Equations Formulas Calculator

Hytera, a leading designer and manufacturer of professional mobile radio communication equipment, offers complete and customized communication solutions to government, public security, utility, transportation, enterprise & business for higher organizational efficiency.

Yamuna Cable Accessories Pvt. Ltd. specializes in the development, manufacturing, and marketing of power cable accessories, including a comprehensive range of cable jointing kits and components. The product line encompasses _Heat Shrink_ and _Cold Shrink_ cable joints, heat shrinkable tubing, pre-moulded slip-on joints, resin pour, and Tapex systems, all designed for applications up to 66 kV. The company highlights its ISO 9001-2015 certification, signifying adherence to international quality management standards in its manufacturing processes. The resource details specific product categories such as end caps, insulation piercing connectors, copper mesh, fireproof coatings, tubing and components, lugs and ferrules, and safety products. It also features specialized items like _Elbow Connectors_ rated for 25 kV-250, 400, and 630 amps, and various types of tinned copper braid used for grounding and electrical shielding. The site provides an overview of their manufacturing capabilities and global presence across 40+ countries. Established in 1973, Yamuna Densons has over four decades of experience in the industry, positioning itself as a significant designer, manufacturer, and supplier of insulators, tabs, and cable jointing systems in India. The company emphasizes its role as a leading exporter of these products, serving both domestic and international clients.

This page offers an online antenna designer tool for Hams to calculate the dimensions needed to construct a coaxial collinear antenna for a specific frequency. It provides guidance on the required frequency input, coax velocity factor, and element measurements for optimal performance. The tool is recommended for experienced antenna builders due to its complexity and technical requirements. Users can input the frequency in MHz and the tool will generate the necessary dimensions based on the chosen parameters. The page emphasizes the importance of accurate measurements and connections for successful antenna construction.

Many antennas and antenna designers neglect the true cause of loss. The major problem using short antennas is the reactance, not the length

The _RS Group_ (formerly Distrelec) provides a comprehensive online store for electronic components, catering to both industrial and amateur radio needs. This resource offers a wide array of parts, including semiconductors, capacitors, resistors, relays, sensors, and power supplies, essential for constructing and maintaining amateur radio equipment. The platform emphasizes efficient procurement and features various top-level categories for easy navigation, such as **Sensors** with 33 subcategories and **Relays** with 13 subcategories, supporting diverse project requirements. Beyond component sales, RS Group offers services like ISO- and DAkkS-certified calibration for over a thousand measuring devices, and e-procurement solutions for businesses. The site also promotes _DesignSpark_, a community and software suite for electronic designers, aiding in the realization of design ideas. This integration aims to provide enhanced local support and a broader product selection, facilitating everything from basic circuit builds to complex industrial automation projects.

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!

This page offers an online antenna designer to calculate the dimensions for a collinear dipole antenna at a specified frequency. The collinear dipole antenna is constructed with multiple 1/2 wavelength sections separated by a 1/4 wave phasing stub in the form of a coil. It requires a ground-plane to operate and can be used for both receiving and transmitting purposes. The antenna can be made from common copper wire, with thicker wire providing a wider bandwidth. The calculations are based on radio waves traveling at the speed of light. Ideal for ham radio operators looking to build their own antenna for improved reception and transmission.

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.

This page allows hams to design a vertical-plane delta-loop antenna for a single amateur HF band in different configurations. By choosing different feed-point positions, operators can observe variations in polarization properties, radiation patterns, and feed-point impedances. Users can generate radiation pattern plots, VSWR charts, antenna current diagrams, and Smith charts for their antennas over various ground types. Through adjusting the antenna's physical dimensions and refreshing the plots, hams can gain insights into the antenna's performance in the field. The page also discusses how elevation radiation patterns may change based on the antenna configuration and feed-point position.

The page for designing linked dipole antennas allows users to swiftly create a versatile multi-band antenna suitable for portable applications in outdoor settings, such as in the field or on mountain tops.

This webpage offers an online antenna designer tool to calculate the dimensions for constructing a double bi-quad antenna for various frequencies. The directional antenna is suitable for UHF and higher frequencies, such as WiFi, UMTS, LORA, and mobile phone networks. It provides dimensions based on the input frequency, making it ideal for hams looking to build their own antennas for specific applications. The tool also mentions using common household materials like copper wire for construction, making it accessible for amateur radio operators with basic equipment.

Online antenna calculator for J-Pole models.

OpsLog is a modern amateur radio logbook application for Windows, designed to consolidate station operations into a single, integrated interface. It provides fast, single-strip QSO entry with automatic lookup from QRZ.com or HamQTH, populating callsign, name, QTH, and grid square. The software offers real-time CAT control supporting OmniRig, native FlexRadio/SmartSDR, Icom CI-V (via USB or internet), and TCI protocols. Key logging features include ADIF 3.1.7 compliance, offline DXCC resolution, a worked-before matrix, and dupe detection. It also incorporates a great-circle map for short/long path calculations and a clickable rotor compass, displaying antenna direction accurately. The application integrates DX cluster functionality with multiple server connections, band map spot display, and customizable alert rules for callsign, country, band, mode, or spotter, delivering notifications via sound, on-screen alerts, and email. OpsLog tracks numerous awards such as DXCC, WAS, WAZ, WAC, WPX, IOTA, POTA, SOTA, WWFF, and DDFM, with synchronization capabilities for ClubLog, LoTW, QRZ.com, and eQSL. For contesting and multi-operator environments, it offers serial number auto-fill, enforced contact windows, live dupe flagging, and shared MySQL logbook support for real-time status updates among operators. Additionally, it includes a QSL card designer with automated layout suggestions.

This webpage caters to EMRFD owners, offering insights into building popcorn receiver band-pass filters with Ladpac programs and EMRFD Chapter 3 knowledge. Through practical experiments and Ladpac tools, the author explores coupling capacitors' impact on filter response and return loss optimization. The content emphasizes empirical approaches, encouraging builders to embrace experimentation and learn from mistakes. Detailed examples and workflow suggestions aid hobbyist-level designers in creating customized filters, fostering a deeper understanding of filter design principles.

This web page offers an online antenna designer tool for hams to calculate the dimensions needed to construct a J Pole antenna for any desired frequency. The J Pole antenna is a simplified version of the Slim Jim antenna, radiating and receiving signals in an omni-directional pattern. It does not require a ground plane, making it suitable for indoor mounting. With the ability to be made from common household wiring, this antenna performs well for both receiving and transmitting purposes. The calculator is based on radio waves traveling at the speed of light and provides metrics in both imperial and metric units.

This article explores the role of velocity factor (VF) in calculating stub lengths for VHF/UHF Baluns. It clarifies misconceptions about VF's relevance, distinguishing between coaxial cable interior fields and external stub fields. Practical examples, such as the Pawsey Stub and Coaxial Cable Balun, are analyzed alongside experimental findings. The results reveal that traditional VF adjustments are unnecessary for stubs with external fields but critical for internal coaxial applications. Historical and theoretical insights provide a comprehensive perspective for antenna enthusiasts and designers.

This project describes a high-performance EME antenna array consisting of two home-designed 9-element Yagis, each about 2.5 wavelengths long, combined into a 25-ohm system and matched to 100 ohms using 9/4λ sections of 50-ohm coax. The array supports rotatable polarity from 0° to 180°, allowing both horizontal and vertical polarization to optimize moonbounce performance under varying conditions. Despite operating for years without a balun—something another designer called “disastrous”—the system has delivered strong results, including copying very weak DX such as VK3KH at about -25 dB with only 120 W (around 2 kW ERP). The builder continues to refine the mechanics, having installed new gear motors and an upgraded follow-up control system in 2011.

This page offers an online tool to calculate the dimensions for a quarter wave antenna based on a specified frequency. It helps hams design antennas for optimal reception and transmission properties, using 1/4 wavelength elements. The calculator ensures a matching impedance of 50 Ohm without the need for additional components. The page is useful for amateur radio operators looking to build efficient antennas for their radio communication setup.