Search results

Distance and directions calculation program using both Spheric, the perfect round earth model, and Vincenty's inverse ellipsoid algorithm, the WGS 84 earth model.

A PDF presentation of a home made moxon antenna for 50 MHz 70 MHz and 144 Mhz. The project is mainly out of surplus plastic Plumbing pipes and clips etc, and also details of how the dimensions were calculated.

The G5RV multiband HF antenna, designed by Louis Varney (G5RV) in 1946, is a popular compromise antenna offering good overall performance on most HF bands when paired with an external antenna tuner. The basic full-size G5RV measures 102 feet across the top for 80 through 10 meter operation and is fed at the center via a 34-foot low-loss feed-stub. This interaction between the radiating section and the feed-stub facilitates matching across 80-10 meters with a standard tuner, often eliminating the need for ladder line directly to the shack. The antenna's design center frequency is 14.150 MHz, configured as a 3/2-wave dipole on 20 meters, with its 102-foot length derived from long-wire antenna formulas. Construction details emphasize the matching section, which can be open wire, ladder line (window-type), or TV twin lead. Each type has a specific velocity factor (VF) affecting its physical length for an electrical half-wave on 14 MHz; for instance, open wire requires 33.7 feet (VF 0.97), ladder line 31.3 feet (VF 0.90), and TV twin lead 28.5 feet (VF 0.82). The article provides formulas for calculating these lengths and discusses the antenna's behavior on individual bands, from 3.5 MHz where it acts as a shortened dipole, to 28 MHz where it functions as two three-half-wave long-wire antennas fed in-phase. Practical construction notes include recommendations for vertical descent of the matching section, sealing the coax junction, providing strain relief, and winding a coaxial choke coil to mitigate common mode current. The resource also presents dimensions for double-size (204 ft) and half-size (51 ft) G5RV versions, along with their corresponding matching section lengths for various line types, making it a versatile reference for hams considering this classic wire antenna.

The Top-Rated Electrical and Electronic Engineering Calculator for Palm OS

HB9DNU Karlheinz's blog, hosted on Blogger, presents a collection of personal reflections and observations, predominantly in German. The content spans various non-amateur radio subjects, including Swiss political initiatives, economic discussions concerning banks like UBS, and social commentary. For instance, an entry from February 2008 details the Swiss vote on a combat jet noise initiative, highlighting the debate between tourism concerns and national security. Another post from October 2008 critiques the 500 billion Euro bailout package for banks, calculating its per-capita cost for German citizens and referencing earlier blog entries from March 2006 and June 2007 that discussed UBS salaries and Raiffeisenbank issues. These entries often reflect Karlheinz's personal perspective on current events. The blog also includes lighter, more personal notes, such as a February 2009 entry about a video produced by his grandson, and observations on local events like a bird exhibition in Contone or a scenic train ride through the Centovalli, demonstrating a broad range of interests beyond the ham radio hobby.

Calculating Antenna Wind Load

Does your Amateur Radio system comply to the EMI rules ? (German values implemented)

A javascript online calculator of bearing and distances by G4VWL

The utility "NEC-2 for MMANA" is intended for calculation of antenna models made and optimized in program MMANA and for construction and simulation of antenna models using input language NEC-2 and based on MMANA models.

Accurately determining an antenna's feedpoint impedance is crucial for optimal performance, especially when experimenting with new designs or making adjustments. While SWR meters provide basic information, a full complex impedance measurement reveals the resistive and reactive components, which are essential for proper matching. Modern antenna analyzers, like the _Palstar ZM30_ or MFJ259B, simplify this task, but measurements taken through a transmission line require careful interpretation due to impedance transformation. This resource details a calibration method to precisely account for the effects of the feedline. It explains how a transmission line can significantly alter the measured impedance, illustrating this phenomenon with a Smith Chart example where an 80m antenna's [22 + j6] Ohms feedpoint impedance transforms to [82 + j45] Ohms after a 10m line. The guide demonstrates using a transmission line calculator applet, such as the one by W9CF, to reverse this transformation. It outlines the process of calibrating a specific length of RG174 coax, showing how an initial 26ft estimate was refined to **25.85ft** to accurately predict a known 22 Ohm load, significantly improving accuracy over uncalibrated results.

A javascript online calculator for popular wire antennas, from the standard easy to build flat-top dipole, to the inverted V dipole, but also the Quad Loop, and the equilateral delta loop antenna

Calculate power loss depending on coax cable you use

Displays amateur radio grid squares worked from third-party logging programs, providing a visual representation of contacts on a world map. This Windows application uses colors to differentiate up to four bands concurrently, calculating the total number of grid squares worked per band. It reads plain-text log files, including fixed-width, character-delimited, ADIF, and Cabrillo formats, dynamically updating the map as log files are saved during contests or general operation. Primarily targeting **VHF** and above operators, WorkedGrids aids in grid square collection for contesting and awards. The software offers a fixed-resolution continental viewpoint, zoom-in capabilities, and supports printing or copying the map to the clipboard. It operates on Windows 95 through Windows 11, requiring minimal CPU and RAM, and features a non-invasive installation. The program has undergone several updates, with version 7 released on March 3, 2024, addressing minor fixes and improving stability.

This online microstrip patch antenna calculator determines the length and width of a microstrip patch antenna for a given frequency

Build an effective dipole antenna that needs much less space by adding two loading coils. This online calculator tells you how.

Helix antenna online calculator with match calculator

An online J-Pole antenna calculator that need just to input the frequency and calculates in inch size of each element

Microstrip Patch Antenna Calculator determines the length and width in millimeters of a rectangular patch antenna.

Demonstrates the construction and implementation of a **two-element phased vertical array** for 40 meters, utilizing _Christman phasing_ techniques. The author, W4NFR, details the process from building individual 1/4-wave aluminum verticals to integrating them into a phased system. The resource covers antenna spacing of 32 feet, elevated radial design, and the critical steps for tuning each vertical to achieve a 1.1:1 SWR before combining them. It also provides insights into calculating precise coax lengths for feedlines and the phasing delay line, emphasizing the use of an MFJ-269 Antenna Analyzer for verification. The finished system exhibits good front-to-back nulls, with an overall SWR ranging from 1.6:1 to 2.2:1, which is managed by an antenna tuner. The project includes detailed photos of the relay box, showing 12 VDC relays capable of handling 5KV, and the control box in the shack for switching between three different antenna pattern configurations. Static bleed-off chokes are incorporated for protection, and the construction emphasizes robust weatherproofing for outdoor elements.

Calculating HF helical whip antenna for mobile or portable operation

This calculator is designed to give resistor values for unbalanced T-pads, and for balanced H-pads.

This page allows you to calculate in the most accurate way high-Q inductor coils.

A page by 9A7PJT dedicated to HB9CV yagi antennas includes link to the HB9CV calculator program and some interesting plans

This calculator is designed to give the vertical length of a quarter-wave ground plane antenna, and the length of each of the four radials for the selected frequency you have entered

This calculator is designed to give the horizontal length of a particular dipole including Tees, antenna, or one side of it, for the frequency chosen. Enter the desired frequency and select the desired calculation from the drop box

Demonstrates the adaptation and construction of a 7-element DK7ZB Yagi antenna for the 4-meter band (70 MHz), utilizing components from a defunct 2-meter CUE DEE Yagi. The resource details the modifications made to the original DK7ZB design to fit the shorter CUE DEE boom length, specifically adjusting element lengths for 6mm rod elements while reusing existing mounting holes for the reflector and last director. It provides precise element lengths for the reflector, dipole (12mm aluminum tube), and five directors, along with a note on cutting elements for transport. The article includes a 4NEC2 simulation file for performance analysis and an SWR plot, confirming the antenna's electrical characteristics. It also specifies the calculation for the quarter-wavelength matching cable using SAT752F coaxial cable, resulting in a 909mm length. Practical application is shown with the finished antenna in operation at JO20XC, listing several activated Maidenhead squares such as JO56PA and JP40KS, validating its effectiveness for portable 70 MHz operations.

An online javascript calculator for cubical quad antennas, simply input the resonating frequency to calculcate up to a five element quad antenna. This quad antenna calculator let you determine the total length of each element and spacing among elements.

W0FMS Two-Wire Beverage (SWA) Transformer Calculator

This free program calculates the location of any locator. It calaculates the distance, azimuth, longitude and latitude between two Maidenhead locators. Converts longitude/latitude coordinates to Maidenhead locator Converts Maidenhead locator to longitude/latitude coordinates

Ever need a way to estimate the amount of wire to add to or remove from a center-fed wire dipole antenna to achieve resonance at a desired frequency? This article help to determine correct wire lenght.

The Receiver Test Data resource is a detailed review database focusing on the performance metrics of various radio receivers. The methodology involves rigorous lab measurements, often adhering to standards such as the ARRL RMDR (Reciprocal Mixing Dynamic Range) and BDR (Blocking Dynamic Range). Specific test equipment and protocols are utilized to assess parameters like noise floor (dBm), AGC threshold (uV), and LO noise (dBc/Hz). For example, the _Icom IC-7300_ is evaluated with a noise floor of **-133 dBm** and an LO noise of **-141 dBc/Hz**, providing insights into its performance under different operational conditions. The resource includes a wide range of models, from the _Elecraft K3S_ to the _Yaesu FTdx-101D_, each tested for dynamic range, sensitivity, and selectivity. The data is sorted by key metrics such as third-order dynamic range and phase noise limitations, with RMDR values calculated by subtracting 27 dB from LO noise figures. This structured approach allows users to compare different receivers' capabilities, focusing on technical specifications and performance outcomes in various scenarios. DXZone Focus: Review Database | Lab Measurements | -133 dBm | ARRL RMDR

Calculating the length of a resonant square quad loop

The ZS6BKW multi-band antenna, an optimized variant of the classic G5RV, is presented with detailed construction and tuning instructions. This resource outlines the antenna's design principles, which were developed by _Brian Austin (G0GSF)_ using computer programs and Smith charts to achieve optimal dimensions. It provides specific guidance on calculating and adjusting the lengths of the radiators (L1) and the matching ladder line (L2), emphasizing the critical role of velocity factor (VF) in achieving resonance. The article includes a step-by-step procedure for empirically determining the VF of ladder line using an antenna analyzer, ensuring accurate physical lengths for the matching section. It details the tuning process for the radiators, offering practical tips for incremental adjustments to achieve the best SWR curve. The resource presents SWR measurement results obtained with an _AIM-4170C_ analyzer across multiple bands, alongside predicted SWR graphs from an AutoEZ model. It confirms successful contacts on 80, 40, 20, and 17 meters, including a **17-meter DX contact** to Italy. EZNEC and AutoEZ models for the ZS6BKW antenna, covering 80 through 6 meters, are provided for download, allowing further analysis and customization. The document specifies component details, such as the use of Wireman 554 ladder line and #14 AWG THHN copper wire, and discusses the antenna's performance characteristics, noting high SWR on 15 and 30 meters but successful tuning on 6 and 80 meters with an external tuner.

Use this online calculator to determine the length of a quarter-wave antenna from the frequency. Both metric and English units of measurement are supported.

A simple 50 ohm dummy load to test transmitters. includes a simple RF diode detector to measure the peak voltage, and calculate the power

Use this online calculator to determine the length of a full-wave loop antenna from the frequency. Both metric and English units of measurement are supported. Quarter-wave matching section lengths are also calculated.

Use this online calculator to determine the length of a dipole antenna from the frequency. Both metric and English units of measurement are supported.

ICNIRP is a calculator software that allows you to determ safety distances for many know amateur radio antennas with respect to ICNIRP limits developed by DL9KCE

Free basic and advanced system design tutorials for every component and aspect of solar power. Plus system sizing calculators, battery bank calculators and wire size calculators

Online calculator and a full documented pictorial guide to build a single sided 8 slot waveguide antenna

This article includes an online calculator for a 3 element Yagi Antenna. The formula and basics theory of Yagi Antenna are also explained with examples.

Designing and constructing portable wire antennas for HF operations, this resource explores several configurations including the _foldback dipole_ for space-constrained setups and an inductively shortened dual-band dipole for 20m and 40m. It details the calculation of inductance for shortened elements, providing a Visual Basic 6.0 program screenshot that illustrates determining coil parameters like turns and length for a **25.5 uH** inductor. The document emphasizes practical considerations such as adjusting wire lengths for optimal SWR, noting that a dual-band dipole achieved SWR below 2:1 on both 20m and 40m, with careful adjustment bringing it under 1.5:1. Further, the resource describes a half-wave antenna matched with a coaxial stub, a method often referred to as the _Fuchskreis_ in German amateur radio circles, to transform the high feedpoint impedance to 50 Ohms. This monoband solution, for a 20m application, uses a stub length of **2.98m** (0.216 lambda multiplied by coax velocity factor) and a shorted stub of approximately 48cm. The coaxial stub design is highlighted for its resilience to ground proximity, allowing it to be rolled up or laid on the ground with minimal SWR impact, making it highly suitable for portable QRP operations.

Types of coax-cable with rf attenuator calculator, line loss calculator form includes an antenna gain calculator. This coax loss calculator can help you on choosing the right cable for your antenna sysmte.

a website by vu2fd with theory lessons, details on rules and regulations and planty of homebrew projects for radio amateurs, java calculators.

Operating magnetic loop antennas requires careful consideration of RF safety, particularly regarding near-field magnetic field intensity. This resource presents calculations for magnetic field strength (H-field) at various distances from a magnetic loop, emphasizing that the H-field is significantly higher than the E-field in the near-field region due to the inductive nature of the radiating element. It provides specific formulas and examples for determining safe operating distances based on power levels and loop dimensions, crucial for compliance with RF exposure limits. The analysis compares calculated H-field values against FCC and ICNIRP maximum permissible exposure (MPE) limits for controlled and uncontrolled environments. It demonstrates that even at QRP power levels (e.g., 5W), the H-field can exceed MPE limits within a few feet of the antenna, necessitating greater separation distances than often assumed for electric field considerations. The practical application of these calculations helps amateur radio operators configure their stations to ensure personnel safety and regulatory compliance when deploying compact, high-Q magnetic loop antennas.

A 4 elements Yagi-Uda antenna for 144.3 MHz plan with dimensions and yagimax dimension calculation

Online calculator, Butterworth Bandstop (Notch) Filter Designer

The HA8TKS VHF DXCluster is an essential online resource for amateur radio operators focusing on VHF and higher frequencies. This platform provides real-time information on DX spots, allowing users to track and engage in two-way radio communications effectively. The integrated map mash-up feature enhances the user experience by visually displaying the locations of DX stations, making it easier for operators to plan their contacts and optimize their antenna setups based on geographical data. In addition to the DXCluster functionality, the site offers various HAM tools, including a QRB calculator, which helps operators determine the distance to DX stations based on Maidenhead grid locators. The platform supports multiple modes of operation, including CW, SSB, RTTY, and digital modes like FT8 and JT65. With a user-friendly interface and comprehensive data, the HA8TKS VHF DXCluster is a valuable asset for both novice and experienced operators looking to enhance their DXing and contesting activities.

Calculate the value of an unknown resistor with this free program for windows

Noise Meter software for the noise meter tool by G8KBB that measure noise using a PC sound card and calculate noise figures by means of a calibrated noise source.