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How can the current "flowing" out of the top of a mobile loading coil be greater than the current "flowing" into the bottom of the coil?

Depiction mapping software can download and integrate maps, elevation plots, weather data, situation reports, damage assessments, volunteer movement, and more. It interface with your APRS ssystem

The Indianapolis Police Scanner on Broadcastify allows users to listen to live police radio transmissions from Indianapolis. The website provides access to emergency communications and public safety broadcasts.

Serving Columbia and Greene Counties of New York State

A Friendly Ham Club!

PACTOR-II is a fully backward-compatible improvement to the original PACTOR system. It is an adaptive mode that applies different modulation and encoding methods depending on the channel quality.

This R.F. current meter was developed to assist in measuring line currents in balance feed lines as used in the All Band HF Antenna.

Operating a ham station often involves encountering radio frequency interference (RFI), RF feedback, or RF burns, which are frequently misattributed to poor equipment grounding. This resource meticulously dissects these assumptions, asserting that RF grounds on the operating desk often merely mask more significant system flaws. It identifies five primary causes for RF problems, including antenna system design flaws, proximity of the antenna to the operating position, DC power supply ground loops, equipment design defects, and poorly installed connectors or defective cables. The content emphasizes that issues like "hot cabinets" or changes in SWR when connecting a ground indicate substantial RF flowing over wiring or cabinets, a phenomenon known as common-mode current. The article provides detailed explanations of common-mode current generation, particularly from single-wire fed antennas like longwires, random wires, and OCF dipoles, which inherently present high levels of RF in the shack. It also illustrates how vertical antennas, lacking a perfect ground system, can excite feed lines with significant common-mode current. Through simulations, the author demonstrates how a dipole without a proper _balun_ can cause RF problems at the operating desk, showing current patterns and voltage distributions on feed line shields. The discussion extends to the proper application of _RF isolators_ and _ferrite beads_, clarifying their role in modifying common-mode impedance on cable shields and cautioning against their use as a band-aid for fundamental system defects. The resource advocates for correcting the actual source of RF problems, such as antenna system issues or poor connector mounting, rather than relying on internal shack grounding or isolators. It highlights that properly functioning two-conductor feed lines, like coaxial or open-wire lines, should result in minimal RF levels at the operating position, even without a desk RF ground. The author shares personal experience, noting that his stations since the late 1970s have operated without RF grounds at the desks, relying instead on proper antenna system design and feed line integrity.

Tait electronics provides advanced and reliable voice and data radio communications products and solutions, specialising in customised solutions for organisations worldwide.

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

Weak Signal Propagation Reporter Network Map and Database of WSPR data

Designing your own QSL card is now easier than ever. This is a Program that helps you design and then Print your QSL cards filling them automatically with QSO data.

First Turkish APRS web site. Many TA APRS Maps for UI-Wiev

The Lassen Amateur Radio Club has been affiliated with the ARRL since 1972

A project of a linear regulated for low noise power supply 16v, 10A

The Short Mountain Repeater Club (W4YXA) maintains an open repeater operating at 146.910 MHz using a negative offset (146.310 MHz). The repeater is located about 60 miles SSE of Nashville, Tennessee

Presentation about finding, restoring, updating and operating vintage Ham Radio by K4QKY and Bill Call, KJ4W

All risk ham radio insurance plans

The TransWorld Antennas TW4040 The Adventurer Monobander™ is a portable HF antenna designed for rapid deployment in field operations, including **SOTA** and **POTA** activations. This manual details the antenna's assembly, tuning procedures, and operational guidelines for optimal performance on the 40-meter band. It outlines the specific components, such as the telescoping whip and base unit, required for proper setup. Instructions cover mast erection, radial wire deployment, and impedance matching to achieve a low **VSWR** across the designated frequency segment. The document also provides guidance on antenna orientation and environmental considerations for portable use. It specifies the antenna's power handling capabilities and physical dimensions when fully deployed and collapsed for transport.

Platinum coast amateur radio society (pcars) w4mlb - melbourne florida, pcars provides hf, vhf, and uhf communications for any police fire and rescue emergency

Located at Bay Pines VA Hospital, Fl

A searchable database of online websdr receivers, lists OpenWebRX, KiWi SDR and WebSDR from all over the world, providing a web interface to search and filter links to websdr

How to setup and install custom filters, usually inrad, into Yaesu FT 857 and FT 897 transceivers

The author explores the VP2E antenna, introduced by Ed Durrant DD5LP, for Portable Operations on the Air (POTA). Detailing its unique design, successful trials, and an unexpected propagation twist, the VP2E proves a promising addition to the author's portable antenna arsenal.

Manual of the BD-35 Dual Band VHF UHF RF power amplifier by Mirage Amp

Turkish ham radio stations with links, and IOTA info, in turkish

Modification leaves nearly all of the existing Omni agc circuitry intact, simply add an audio detector which modifies the delay characteristics of the original system by G3IXQ

Explains the fundamental principles of Software Defined Radio (SDR) and Digital Signal Processing (DSP) within the amateur radio context, serving as an initial entry point for hams interested in these technologies. It covers the architectural shift from traditional analog hardware to software-centric radio systems, detailing how digital signal processing algorithms are applied to modulate, demodulate, and filter radio signals. The resource compiles a list of external links to _white papers_ and project pages, offering further technical depth. This page provides a foundational understanding of SDR/DSP, enabling operators to grasp concepts like direct sampling and quadrature mixing. It references various projects and discussions, allowing users to explore practical implementations and theoretical underpinnings. The curated links direct users to resources that might cover specific SDR hardware platforms or software applications, facilitating deeper research into the subject.

A presentation of the Yagi Antennas, and other interesting tid-bits by Brian Mileshosky. The document provides an in-depth exploration of the Yagi-Uda antenna, detailing its historical development, design principles, and performance characteristics. Originally described in the 1920s, the Yagi antenna features a driven element and parasitic elements, including reflectors and directors, which collectively determine its behavior. The document highlights how element lengths, diameters, and spacing influence gain, impedance, and directivity. It also discusses the antenna's reciprocal nature and presents data on typical gain values for various element configurations. Additionally, the text covers practical considerations, such as the construction of a "Tape Measure Yagi" for amateur use, and touches on related antenna types like dipoles and their application in Near Vertical Incident Skywave (NVIS) communication.

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.

A Six element antenna for the 50 MHz Amateur Radio Band v4 by DF9CY

A sharewave windows logging program for the ARRL 10 meter contest by N3FJP

Batterieries for ham radio handheld radios and more

It is not always possible to tackle the sources of local QRM. What remains is trying to reduce the noise level by means of your antenna system. Learn how to reduce QRM and understand how cancell noises.

Mobilinkd Bluetooth APRS TNC. With your radio, your Android phone and this TNC, you have everything you need to get started with APRS.

Solar Panels Grid Tie Systems, Kits, Fountains, Chargers and more

Handcrafted sending instruments for the Morse enthusiasts. K4VIZ Morse keys and paddles manufactured by K8UL.

The Radio Reference Database for United States

W4YCH & W4MLF Home Page

Site officiel du world lighthouse on the air award - official web site for wlota award

ARRL Resources about Lightning Protection for the amateur radio station

Solar panels manufacturer based in spain

Macedonian press agency

NT9K Personal Amateur Radio Website from Melbourne Florida

VHF/UHF Contest Logger is a windows freeware contest log program that supports ARRL VHF/UHF contests and other popular VHF contests

CASPERARC amateur radio club in Casper Wyoming

This article serves as a beginner-friendly guide to constructing a simple VHF dipole antenna for 2 meters, perfect for novices in the hobby. With an emphasis on affordability and simplicity, it explains the basics without overwhelming technical details. Recommendations for coaxial cable and mounting methods are provided, offering practical solutions for effective communication. By following these instructions, novices can build a functional antenna without breaking the bank.

The page provides circuit improvements for the Kenwood TS-440S transceiver, addressing issues such as distortion in SSB signals, limited transmit frequency coverage, lack of crispness in RX audio, and flat audio response. The fixes include adjusting bias, cutting specific components, and changing capacitors to improve performance.

Comparison of all the oscilloscopes available for hobbyists, digital oscilloscopes that you can get for under $500, or oscilloscopes that you can build yourself.

Gnerate morse code at various speeds and with lots of different types of content, everything from individual letters up to a full QSO.