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2m 70cm 23cm Low noise Amplifiers, 3 Low noise amplifiers Outdoor unit with DB6NT parts completed.

An technical page on coaxial cables that describes what coax cables are, how do coax cables works, what are RG cables and difference with several coax cable types, what they are used for, connector types and cable sizes

This article is an attempt to shed some light on this misunderstood component, covering topics like why you need a common mode coke, what it does, what properties it should have, ho to build one and how to measure its performance.

Icom IC-R9500 Professional Receiver with 5 roofing filters, 48 kHz DSP

The CWJF Group began in the 80's with the ideas of an excellent telegrafist, our dear friend Julio (PY4AG) who with customary cordiality taught those interested in practice of morse code.

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

VP9KF Log Online Search Page

Magnetic loop receive antennas manufacturer. W6LVP loops cover 2200 through 10 meters (135 kHz through 30 MHz) with no tuning or adjustment.

The York Radio Club has been serving the Interests of Amatuer Radio for over 78 Years, since its inception in 1936

Harald with be QRV from Kigali, Rwanda from 5th to 24th June 2018 He will be running CW, SSB, RTTY and the new FT8 Mode

Mad your own simple FS meter. It is the simplest thing to make and is good enough to see if the antenna under test is radiating more power than your old ground plane, old mobile vertical or just radiating at all in a particular direction or in all directions.

A Magnetic Loop Controller project details the construction and operation of an automatic tuning system for magnetic loop antennas, which are resonant circuits using an oversized inductor and an adjustable capacitor. The system employs a stepper motor to precisely adjust the variable capacitor, maintaining optimal resonance across the HF bands. It integrates with various transceivers, including _Icom_, _Kenwood_, and _Yaesu_ models, by monitoring the VFO frequency and adjusting the loop's tuning accordingly. The project provides comprehensive building instructions, a PowerPoint-style presentation, and the full source code for the controller's firmware, enabling hams to replicate and customize the design. The controller's firmware offers diverse functionality, including automatic frequency tracking, manual tuning, and SWR monitoring, significantly enhancing the operational efficiency of magnetic loop antennas, particularly for QRP and portable operations. The design emphasizes accurate capacitor positioning, crucial for achieving low SWR and maximum radiated power. Comparisons with manual tuning methods highlight the benefits of real-time adjustment, especially when operating across different bands or making frequent QSYs. The project's detailed documentation and available source code facilitate experimentation and modification by advanced builders, allowing for tailored performance characteristics.

Raspberry Pi Telemetry Station project by Burns Fisher, WB1FJ , Chris Thompson G0KLA/AC2CZ. A step by step guide on Building a Fox-In-A-Box The Easy Way, A Prebuilt SD Card Image or from scratch.

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

Official PDF guide to WSJT-X FT8 SuperFox operating mode published on June 2024 by Joe Taylor, K1JT

World Time Zone is an online quick reference chart that displays the world time zones in detail. DST is also indicated by yellow markers on the map. UTC difference is marked with different colors, and if you point and click will show up area details

World Wide Digi DX Contest 2019 The contest will occur over 24 hours on August 31 and September 1, 2019 using the FT4 and FT8 modes on the 160, 80, 40, 20, 15, and 10-meter bands.

An FLdigi computer interface from spare parts made with a mic modification

3B7A Amateur Radio Expedition to St Brandon - April 5 to 17, 2018

A medium power End Fed Half Wave Antenna coupler, specifically tuned to the QRP frequency of 7030 kHz. Constructed from coil stock and capacitors, it achieves an impedance ratio of 64:1. The coupler has proven effective for power ranges from 2 to 100 Watts on the 40m band.

The database of Chinese ham radios. We are here to show you that you do not need expensive kit from big brands to have fun with ham radio. With the explosion of open source designs, cheap manufacturing, and global delivery, you can now get on the bands and explore for less than ever before.

Showing aircraft scatter reception in action.

GB3WX - GB3WSX - GB3YS

Integrating a **160-meter vertical wire antenna** with an existing 80-meter Yagi system presents unique challenges for Top Band operation. This project outlines the author's experiences with seasonal antenna removal and reinstallation, a necessary task for agricultural land use. It details specific issues encountered, such as incorrect coil sizing and relay configuration problems, providing practical insights into common pitfalls. The article describes the iterative tuning process, comparing **NEC model** predictions with actual on-air performance. It emphasizes the importance of precise measurements and adjustments to achieve optimal resonance and impedance matching. The author shares lessons learned from troubleshooting, including the impact of ground system integrity and feedline considerations. Concluding with an antenna checkup, the resource addresses long-term maintenance aspects, including galvanic corrosion prevention and general upkeep for reliable operation.

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.

Presents a detailed construction guide for a 9 dB, 70cm collinear antenna, utilizing readily available _RG58/U_ coaxial cable and PVC pipe for housing. The resource outlines the critical calculations for ½ wavelength sections at 444 MHz, incorporating the coaxial cable's velocity factor of 0.66, which yields a section length of 223 millimeters. It specifies the preparation and soldering of eight such half-wavelength sections, each cut to 231mm to allow for trimming, forming the core of the array. Further instructions detail the integration of a ¼ wave element (169mm #16 solid wire) at the top and a ¼ wave aluminum tube (160mm, 5/16 inch) at the bottom, crimped to the feed point's braid. The guide also addresses RF common mode current suppression by suggesting the use of _FT50-43_ toroids on the feedline. Final assembly steps cover mounting the antenna within ¾" PVC pipe using a wooden dowel, waterproofing connections, and initial SWR checks. The article also discusses scaling the design for different element counts and other VHF/UHF bands.

A 20 cm mobile antenna design is presented, addressing the need for compact, mechanically stable solutions for VHF/UHF mobile communications. This resource details the _SN 1/8_ antenna, an alternative to traditional quarter-wave or 5/8-wave whips, specifically engineered for robust performance in dynamic, moving environments. The design emphasizes a spherical radiation pattern, which is claimed to enhance signal reflections and contribute to a 2 dB gain over standard mobile antennas, making it suitable for vehicle installations where discretion and vibration resistance are critical. The construction guide includes diagrams and practical considerations for building this antenna, which is noted for its ease of installation and resilience. The design's compact form factor and inherent stability are key advantages for mobile operators seeking reliable and efficient communication without the bulk or fragility of longer antenna systems. The resource, authored by _F5SN_, provides a practical approach to improving mobile station effectiveness.

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!

The Squirrel Cannon article humorously recounts the author's struggle with troublesome squirrels and his creative efforts to deal with them. Frustrated by failed attempts using bamboo spears and slingshots, the author ultimately constructs a spud gun—originally intended for launching antennas into trees, but humorously rebranded by his wife as a "squirrel cannon." The article provides step-by-step instructions, a parts list, and a line drawing for building this practical spud gun, making it a useful tool for antenna enthusiasts while serving as an amusing anecdote.

A collection of dynamically produced images based on the daily data of the NOAA Space Weather Prediction Center

This project details the creation of a portable GoBox housing an IC705, Windows 11 PC, and Bluetooth microphone. The robust setup, enclosed in a weatherproof Hofbauer Explorer Case, ensures stability and functionality for QRP and emergency radio activities. The aluminum-mounted devices minimize RF interference, and a built-in LifePO4 battery powers the 10.1 TFT touch LED monitor, providing approximately 12 hours of use in receive mode. With a focus on grab-and-go versatility, this GoBox stands as an efficient solution for outdoor ham radio operations.

This utility program shows the impedance and reflection coefficient parameters (SWR, reflection coefficient magnitude Rho, or Return Loss RL in dB) at both ends of a transmission line and the details of power loss in the line. It includes built-in specifications for approximately 100 different line types. You can modify the specs to see how small changes affect the results or to specify custom lines. All program inputs may be changed directly or you can use spin buttons to make the changes.

New IOTA activation from AF-118 Los Farallones Island July 25-30, 2019

This article clarifies the roles of baluns, ununs, common mode chokes, line isolators, and impedance transformers in amateur radio. A balun decouples balanced antennas from unbalanced feed lines, preventing interference. Ununs serve a similar purpose for asymmetrical antennas. Common mode chokes and line isolators suppress common mode currents, reducing noise. Impedance transformers adjust antenna impedance to match feed lines but do not decouple or suppress common mode currents. Understanding these components is crucial for optimizing antenna performance and minimizing interference.

Aircraft can also be used to increase communications range, by using Aircraft Scatter

Practice these operating techniques so you will be ready to capture that 100-point bonus on Field Day. QST Article

H40GC DXpedition 2017 DXpedition to TEMOTU Province

Modeling an antenna over real terrain gives you a visual picture of how terrain impacts performance. You can use a model to determine optimum height for antennas on an existing tower, Compare different tower locations for performance, Compare different sites for performance

dBm to watts conversion calculator and explaination on how to convert dBm to watts, including dBm to watts conversion table

How to easily receive and decode CubeSat telemetry

RF Power measurement using a DVM, RF Power measurement using an RF detector, RF Power measurement using an Oscilloscope and using a Spectrum Analyzer

The adventures and stories of M0AUW in the UK

Ham-Yota.org is the official YOTA Youngers on the Air official web site

A comprehensive overview of a 10-band attic antenna system developed for contesting and DXing is presented, covering its evolution and performance. Initially intended in a restricted location, the system has been developed through numerous iterations, using various antenna types such as delta loops and Yagis. Automatic switching, dual-direction capability, and optimum tuning for certain band segments are among the most notable features. The project not only improves operating efficiency but also provides great learning opportunities in antenna design and installation in restricted places.

Repairing an Anritsu MS2711A handheld spectrum analyzer

Professional Lithium-ion battery packs factory in Shenzhen China with more than 11 years experience in Battery business. Manufactured of Lithium ion and lithium polymer battery and Lithium battery packs.

In this survey some practical experiences were written down, that might become handy in case you are contemplating purchasing such an amplifier.

Special callsign PA6FR during Dutch PACC contest

tk8500 is open source software designed to control and program the ICOM IC-R8500 receiver.

144MHz 2m Portable Yagi VHF Beam Antenna. This page contains construction details on a 2 metre 144MHz VHF Yagi beam antenna, designed for portable use.