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ARI Senigallia, Marche Italy

The Bazooka antenna, a coaxial dipole, functions as an omnidirectional antenna with vertical or horizontal polarization. Patented in 1939 and refined in 2006, it features a quarter-wavelength coaxial cable with separated conductors. The outer conductor connects to a sleeve, while the inner conductor extends vertically. Initially complex, it has been simplified for versatile use, including military applications. Adding elements can modify its behavior for NVIS or Yagi-Uda configurations. Experiments in 2007 at the Campus de Pesquisas Geofísicas in Paula Freitas-PR demonstrated consistent VHF and UHF performance, showing reliable return loss measurements despite variable weather.

DL7JV shares his practical experience building and testing capacitive antennas, initially skeptical of their performance compared to magnetic loops and mono-band dipoles. His interest was piqued after hearing a Spanish station running 100 Watts on 80 meters with a 1-meter Micro Vert, making DX contacts into PY and UA0, despite the antenna being only 4 meters high in a garden. This prompted DL7JV to investigate further, consulting resources from DL7PE and DL7AHW, the latter providing DOS programs like "Mitspule.exe" and "Spulenprg.zip" for calculating antenna dimensions and coil conversions. The article outlines the construction of two prototype antennas: one for 7.050 MHz using a 75mm PVC pipe and another for 3.550 MHz with a 110mm PVC pipe. Both designs feature aluminum foil condensers and coils wound from 1mm² H07V-K wire. DL7JV provides specific measurements for the condenser capacitance, surface area, diameter, height, coil inductance, turns, and wire length for both 40m and 80m versions, along with RG58 feedline lengths. Initial reception tests for the 7 MHz antenna, placed indoors, yielded impressive S9+5 signals from a German station compared to an S8 from a 42-meter roof-mounted loop, even hearing a Japanese station. Transmission attempts on April 4, 2004, despite moderate solar storm conditions, resulted in successful QSOs on 7 MHz with EA5OT (579/559) and on 3.5 MHz with YT1NT (579/559) and G4KKI (579/559) using 100 Watts. DL7JV notes the antenna's sensitivity to coordination and feedline layout, suggesting a modification from DL7AXO involving a 500pF fixed capacitor and coil tap for improved SWR stability. He concludes that while the capacitive antenna is space-saving and performs well for reception and 100W transmission indoors, its transmit performance doesn't yet match larger antennas, with further outdoor field tests planned. DL7JV also intends to build a 1.8 MHz version.

IQ2VA ARI Sezione Busto Arsizio

On the field comparison among C-Pole antenna, an EFHW vertical antenna and an Inverter V dipole antenna. Test is done using two identical WSPRLite beacons that transmit with 200mW on the WSPR frequency and analyzing spotted results.

how I learned to stop worrying and love the magic smoke

a subcommittee of the Amateur Radio Council of Arizona

ARI sezione Perugia IQ0PG

A distance of 1/8 lambda between the antenna and the vehicle roof is suggested for optimal performance, with slight adjustments possible to lower the take-off angle for terrestrial contacts. This resource details the adaptation of an _Eggbeater_ antenna for mobile use, specifically for VHF operation, leveraging the car's metal roof as a ground plane. It illustrates the mounting method, repurposing a magnetic ski carrier base, and describes the integration of coaxial relays for polarization reversal, a feature also applicable to UHF versions as discussed in "_Eggbeater Antenna VHF/UHF – Part 2_". This mobile configuration proves effective for satellite communications, such as through the International Space Station (ISS), while also maintaining strong performance for land-based radio contacts. The inclusion of switches with indicator lights for VHF and UHF polarization control, powered by the vehicle's battery, highlights practical considerations for field deployment. The system's adaptability for portable operations underscores its versatility beyond fixed mobile installations.

HARIG is the radio club for people in and around the Harwich area in NE Essex on the east coast of the United Kingdom.

ARI Primiero Trentino Alto Adige Italy

Unlock the secrets of RF signal optimization in a presentation covering Balun essentials, diverse types, SWR Analyzer checks, revealing results, Ferrite impedance measurements, and practical applications on feeders and house conductors.

This article describes a multi-band antenna design for amateur radio enthusiasts by G3FEW. The antenna is designed to cover at least five HF bands with low SWR and without the need for an ATU. It is also designed to be easy to construct and adaptable for different locations. The antenna is a full-wave dipole with traps at the quarter-wave points. The traps are used to tune the antenna to different bands. The antenna can be fed with a 4:1 balun. The article includes instructions for building the antenna, as well as information on the theory behind its operation. The author also discusses the results of his tests with the antenna. This multi-band antenna is a well-designed and versatile antenna that can be used by amateur radio enthusiasts on a variety of bands. It is relatively easy to construct and can be adapted for different locations.

The Ontario QSO Party (OQP), an annual event, takes place on the third full weekend of April, specifically from 1800Z April 18 to 0300Z April 19, 2026, and 1200Z to 2000Z April 19, 2026. This **QSO party** encourages stations outside Ontario to contact as many Ontario amateur radio stations as possible, while Ontario stations work both in-province and worldwide. Key rule changes for 2026 include phone QSOs now counting equally with **CW** QSOs (2 points), the introduction of VE3RHQ as a bonus station, a 250m county line proximity definition, and a new Fixed County Line Category, alongside an adjustment of contest times. Established in 1998 by Bob Chandler VE3SRE, the OQP has been managed by Contest Club Ontario (CCO) since 2006. The event contributes to the State QSO Party Challenge, offering various award categories and maintaining records of past performance. Participants can submit activation plans, review Ontario multipliers, and access county maps. Final results and certificate winners are published, and a dedicated groups.io discussion group facilitates community interaction and support for logging software.

Operaring portable during field day by VK4ADC

ARI Sezione Varese

Since January 1, 1982, 1A contacts have been eligible for **DXCC** credit, making the prefix highly sought after by the amateur radio community for over 41 years. The 1A0C station, operated by the Order of Malta's Italian Relief Corps (CISOM), engages in DXpedition activities with a dual purpose beyond simply providing a rare "new one" for DXers. For instance, the July 26 - August 2, 2023, operation specifically channeled received donations towards reconstruction efforts for flood victims in Romagna, aligning with CISOM's humanitarian mission. The site outlines CISOM's broader scope, which includes impartial humanitarian relief, medical assistance, and emergency support for natural disaster victims, emphasizing respect for diverse beliefs. This approach integrates high-profile amateur radio operations with significant charitable outcomes.

Yaesu FT-710 AESS MF/HF and 6-Meter Transceiver review on QST

ARI Lomazzo Como

ARI Sezione Albino BG

What is antenna polarization, and why does it matter. Horizontal versus Vertical versus Circular polarization. Undestanding how antennas perform better with different polarizations.

Operating marine mobile with antennas for 15-17-20 meters band.

This page details (in brief) the component changes to modify a Cybernet series 27MHz CB transceiver to 50MHz.

If your multiple transceiver station is suffering of intrastation interference, this handy and inexpensive band pass filters and help you. QST article Sept 1988

List of Worldwide HF Beacons published by RSGB. The beacon service is a vital part of amateur radio propagation knowledge. Updates to the HF list, which is is a heavily edit form of the G3USF list, are continued by the current committee. It now only contains beacons that are known to be active and have been heard recently.

Arizona QSO party web site

Article on portable HF antenna where author diverge about antenna efficiency versus size based on his personal experience on using HF antennas during portable operations

Mounting on roof at the right ground level can greately impact on antenna performances because will affect the radiated angle of energy.

A polarity checker is a very useful item to have around the shack and in a go-kit. This project, inspired by a QST article on powerpole connector protection illustrate how to build a polarity checker.

Make your own dipole for 40 and 80 meters band, assembling standard product parts like 40 meter traps, the 1:1 balun and insulators

The document discusses the classifications of sunspots and their potential for solar flare activity, categorizing them into Alpha, Beta, and Delta groups based on their magnetic field characteristics. It explains how these classifications relate to the likelihood of solar flares, ranging from minor to extreme events. The report also outlines the geomagnetic indices and conditions that affect high-frequency (HF) radio propagation, emphasizing the effects of solar flares on radio communication and geomagnetic storms. The information is geared towards amateur radio operators, providing insights into how solar activity influences HF radio operations.

From 24 January to 14 of February 2015 a group of SP hams will be sailing in the area of the Caribbean from J6 J8 J3 FM

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.

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.

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

To get this award one should receive and decode at least one picture in the session. The quality of the received image does not have to be perfect, but good enough to be able to identify. The picture does not have to be full. It is acceptable to send just some part of the picture as well.

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.

A Trapped dipole inverted V antenna for lower HF Bands. Construction details are for temporary installation. Permanent installations will require additional ruggedising and waterproofing however the basic electronics concepts remain the same. This project includes SWR plots for the three bands and pictures details of the homemade traps.

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.

An Excel sheet calculator for the T2FD wire antenna. The sheet has been proved to work either on LibreOffice and Apple Numbers. Just input the resonating frequency to get the proper size and dimensions.

This article presents the C-Pole antenna project, a compact, ground-independent vertical antenna designed for amateur radio operators. It features a folded half-wave dipole configuration that eliminates the need for radials, making it suitable for various locations, especially in deed-restricted areas. The C-Pole offers efficient performance with a 2:1 SWR bandwidth of approximately 3%, and it can be easily constructed using common materials. Additionally, the article discusses practical aspects such as feed-point impedance transformation and balun design to optimize functionality and minimize losses.

Track aircraft by reprogramming an inexpensive digital TV USB stick to receive Automatic Dependent Surveillance-Broadcast signals.

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.

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.

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.

This site is dedicated to helping D-STAR users world wide. From basic information on what D-STAR is to detailed technical information, This site can hopefully solve any of your cravings

A simple 2-tone-generator for testing the linearity of SSB transmitters. This device is as simple as useful. With 2 transistors and an oscilloscope, it is fairly easy to test the linearity of your SSB transmitter. The 2-tone-method is a standardized test method that can be used to determine the maximum output and the amplification characteristics of a sideband transmitter.

Exploring LoRaWAN Range, comparing the performance of 1Watt and 100mW LoRa trackers on daily commute. Analyzing APRS tracks, beacon statistics, and visual comparisons to uncover insights and surprises in the world of long-range wireless communication.

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.

This project details the construction of a compact, circularly polarized Quadrifilar Helix Antenna (QHA) designed for 146 MHz operation. The antenna features a 1/2λ1/2λ helical design with a 2.6:1 aspect ratio, providing 4.5 dB gain and a spheroid radiation pattern. It is ground plane independent and compatible with both vertical and horizontal polarizations, making it ideal for terrestrial and space communications. The design includes step-by-step instructions for building the antenna using readily available materials like aluminum rods, PVC pipes, and RG-58 coaxial cable. The antenna's performance has been validated through comparisons with commercial omnidirectional antennas, showing superior results.