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This QRZ.com callbook entry by DL6GD details the construction and performance of a **40m/80m Morgain folded dipole antenna**. The resource includes a schematic diagram, construction photos, and tuning notes. The antenna, with a total length of **20.30m**, was mounted at a height varying from 4m to 6m above ground. Construction utilizes 0.75 sq mm transparent insulated copper wire, with Plexiglas spreaders (5mm thick, 70x10mm) spaced at 25mm intervals, secured with hot glue. A waterproof junction box houses the feedpoint and balun. Tuning involved adjusting wire bridges for resonance on each band. On 80m, an SWR of **1.1:1** was achieved at 3.657 MHz, with an SWR of 2.7:1 at 3.580 MHz and 2.5:1 at 3.755 MHz, yielding a bandwidth of 175 KHz. For 40m, an SWR of **1.1:1** was measured at 7.100 MHz, with 1.5:1 at 7.000 MHz and 1.3:1 at 7.200 MHz, providing a 200 KHz bandwidth. DL6GD notes that 80m tuning exhibits slight height sensitivity, while 40m tuning is less affected by height or 80m adjustments. Long-term observations from 2014 and 2022 document SWR degradation due to environmental factors like spiderwebs and ice accumulation, which can cause HF-conductive paths between elements. DXZone Focus: Callbook Entry | 40m/80m Morgain Dipole | SWR Measurements | 20.30m Length

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.

A free to download and print, paper log sheet useful for portable amateur radio operations, in a PDF file.

This online article provides a list of individuals who hold or have held amateur radio callsigns, detailing their public recognition. The resource identifies specific callsigns such as **K1JT** (Joe Taylor, Nobel Prize in Physics), **W6OBB** (Art Bell, syndicated radio personality), and **JY1** (King Hussein of Jordan), linking them to their non-amateur achievements. It also notes operational statuses like _Silent Key_ for deceased operators and _lapsed callsign_ for inactive licenses. The article includes information on callsign changes due to vanity callsign programs and provides examples of individuals involved in specific technical areas, such as Percy L. Spencer (**W1GBE**), inventor of the microwave oven, and Jay Kolinsky (**NE2Q**), inventor of electronic sirens. It also references amateur radio involvement in _space missions_ for individuals like Owen Garriot (**W5LFL**) and Helen Sharman (**GB1MIR**). DXZone Focus: Online Article | Famous Hams | Callsign Status | Vanity Callsigns

Over 47 full-screen maps are available within _NAOMI_ (North American Overlay Mapper), a free Windows program designed for US and Canadian amateur radio enthusiasts. This mapping suite includes 9 backgrounds such as CQ Zones, ITU Zones, and ARRL Sections, along with 16 foreground layers like Counties, Areacodes, and Grid Locators. Users can calculate distances and bearings, track real-time mouse positions with continuous Grid-Locator data, and integrate with APRS for live station tracking via the FindU database. For a global perspective, the _Global Overlay Mapper_ (GOM) provides a world map, 8 continental maps, and 29 sub-continental maps, all with 12 active layers including Country Outlines, CQ/ITU Zones, and Prefix information. Both NAOMI and GOM offer feature-locate systems to jump to positions based on prefixes, capital cities, or Grid Locators, and provide customized beam headings and distance displays. The site also features _LogView_, a post-contest log visualization tool that analyzes Cabrillo-format logs by plotting QSOs on maps, supporting over 30 major contests like CQWW and ARRL DX, and allowing comparison with published results.

This online guide details the microphone pinout for the Kenwood TR-7950 transceiver, specifically addressing the wiring configuration for a dynamic mobile microphone with a **500 Ohm** impedance. It provides a pin-by-pin breakdown for the 6-pin microphone connector, identifying the function of each active pin. The resource specifies that Pin #1 is for the microphone audio (white wire), Pin #2 controls the _PTT_ (black wire), Pin #3 activates the memory down function (blue wire), and Pin #4 controls the memory up function (red wire). Pin #6 is designated as the ground connection, while Pin #5 remains unused in this configuration. The document focuses on the physical wiring necessary to restore microphone functionality to the Kenwood TR-7950, a transceiver capable of **45 watts** output on the _2m band_. It directly addresses the technical challenge of re-establishing correct electrical connections after microphone wires have been disconnected from the connector. The information facilitates proper microphone operation for simplex QSOs and other voice communications. DXZone Focus: Online Guide | Microphone Pinout | Kenwood TR-7950 | PTT Wiring

The "Time Zone Map" is presented as a JPEG image file, providing a visual representation of standard time zones across the globe. This resource directly supports amateur radio operations by enabling quick conversion between local times and Coordinated Universal Time (UTC), which is essential for logging contacts, participating in contests, and scheduling DX operations. The map delineates the various time offsets from the prime meridian, offering a practical reference for hams worldwide. Its utility extends to planning international contacts, understanding propagation windows relative to different geographical regions, and ensuring accurate timekeeping for QSL card exchanges. The visual format of the map allows for rapid identification of time differences between a station's location and potential DX targets, simplifying complex time calculations. This specific image file serves as a straightforward, readily accessible operating aid, directly addressing the need for time zone awareness in the amateur radio community. It is categorized under Operating Aids for Travelling, Time, and Maps, reflecting its broad applicability.

Current time in different time zones

The Super Check Partial database files provide a list of callsigns used by active contesters. The data comes from Cabrillo logs contributed by contesters themselves. Contributed logs from the past 24 months are used to create the database. These logs are combined and filtered so that they result in a fairly good (but not perfect) list. The files do not contain any QSO data, such as state, CQ zone, Maidenhead Grid Locator, etc. The dta files can be used with CT, WriteLog, TRlog, SD, N1MM Logger, NA, Win-Test, and others

This World Clock displays time in two user selectable time zones. Each time zone can be switched between 12h and 24h format.

The widest range of stocked components for the electronics, electrical and mechanical engineer.

Presents _HamQTH_, a free online callbook and callsign server, which provides rapid XML access for various logging programs, enabling seamless integration for amateur radio operators. The service includes features such as recent activity logs, propagation predictions, and support for multiple languages, making it a versatile tool for DXers and contesters. It also offers detailed information on callsigns, including US states, counties, IOTA, WAZ, and ITU zones. Users can leverage _HamQTH_ for efficient log searching and to monitor current band conditions, aiding in planning DX operations and contest strategies. The platform's XML interface facilitates automated lookups, streamlining the process of identifying stations and gathering essential QTH data. Petr Hlozek, OK2CQR, developed this resource, reflecting practical experience in amateur radio data management.

This was the blogger home page of the Resonant Frequency podcast. Follow the link to get to new web site.

A large printable PDF file representing the world time zones. This map gives an overview of current local times around the world. If you ever asked yourself what time zone am i in, find your answer here.

The 3Y0K Log Online provides a detailed logsearch interface for the **3Y0K** DXpedition to Bouvet Island, scheduled for February 2026. This web-based tool, hosted on _Club Log_, allows users to access real-time QSO statistics and leaderboards. The interface includes interactive features such as a map for checking real-time propagation and colored boxes that reveal mode and time breakdowns when hovered over. The service supports HF bands and provides a structured overview of QSOs, including band/mode breakdowns and continent-specific data. Users can report logging inquiries and QSL requests exclusively through the M0OXO Online QSL Request System (**OQRS**). The site also offers additional resources like band plans, operating practices, and FT8 advice. The leaderboard feature, which includes clubs and Contest Club, ranks stations based on the number of band slots worked, with duplicate QSOs being discouraged. The expedition's impact on users' totals is also tracked, providing insights into new bands, modes, and DXCC entities worked. DXZone Focus: 3Y0K DXpedition | Club Log | Bouvet Island

An amateur radio contest log sheet printable in A4 format, useful for portable operations, free to download PDF File.

Useful exercise sheet to learn morse code reception. In A4 format PDF File, it contains groups of 5 characters commonly used while learning morse code reception.

Explore this high-resolution ITU Zones Map, a critical reference resource for amateur radio operators, international broadcasters, and telecommunications engineers. Originally established by the International Telecommunication Union – Radiocommunication Sector (ITU-R) Broadcasting Services Division (1999), this chart accurately divides the globe into 90 specific CIRAF zones. This authoritative visual guide is indispensable for planning High Frequency (HF) radio propagation, scheduling international broadcasts, and verifying locations for radio contests and awards. Distinct from the 40 CQ Zones, the ITU zoning system provides the official administrative framework used for global frequency management. This digitally enhanced version ensures maximum clarity of zone boundaries and numbering (e.g., Zone 28 for Central Europe), making it an essential tool for technical accuracy in logbooks and station management. It serves as a trustworthy standard for educators, hobbyists, and industry professionals alike.

This PDF document details the construction of a **70 MHz** Big Wheel antenna, a horizontally polarized omnidirectional array. The design utilizes three full-wave loops, each approximately **2160 mm** in diameter, arranged in a triangular configuration. The resource provides mechanical dimensions for the antenna elements and a comprehensive bill of materials, specifying component quantities and types, such as M8 stainless steel bolts, 15x15x1.5 mm square aluminum tubing for spacers, and 8 mm aluminum rod for the arcs. The central hub is constructed from two 160x160x8 mm aluminum plates, with four 40 mm long polyamide insulators supporting the radiating elements. The feed system incorporates a 50 mm diameter aluminum pipe for mounting and a matching stub constructed from a 120x20x2 mm aluminum sheet, connected via M8x10 mm bolts. The resource includes a diagram illustrating the mechanical dimensions and assembly points, including the N-connector fixing point and the center conductor attachment. The project was published on May 25, 2011, by Peter OE5MPL and Rudi OE5VRL. DXZone Focus: PDF | 70 MHz Big Wheel | Mechanical Dimensions | **2160 mm** loop diameter

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

The County Hunting software, version **6.1**, is designed for amateur radio operators focused on USA-CA Award tracking and logging. This application supports _Windows_ environments and facilitates the import and export of ADIF files, enhancing QSL management by integrating electronic confirmations via LoTW and e-QSL. The software has been updated to align with the new award rules managed by MARAC, following the discontinuation of CQ magazine's involvement. Users can visualize QSLs post-scanning and benefit from enhanced ADIF import functionality. Version 5.4 introduced accelerated county searches via FCC databases, with filters for QSL confirmations and e-QSL enhancements. The software also includes a feature for backing up and restoring QSOs by LoTW confirmations. Visual County tools have been refined, offering improved map interactions and the addition of county flags. The software supports various digital modes including FT8, FT4, and SSTV, and includes functionality for PSK250 and 60m bands. The application is multilingual, with support for Italian, English, French, and Spanish, and provides automated updates and web-based county searches. DXZone Focus: County Hunting | ADIF | Windows | LoTW

This web article by VK3BLG details the construction of an experimental 70cm (432 MHz) circularly polarized patch antenna, intended for satellite communication. The resource provides dimensions, feed point specifications, and impedance matching considerations for a single patch element, with discussion extending to array configurations for circular polarization. Construction involves a copper patch element on a dielectric substrate, fed via a coaxial cable. The design is based on information derived from AO-40 satellite antenna specifications, focusing on achieving circular polarization for satellite reception. The article includes specific dimensions for the patch and feed points, along with impedance values. Validation is implied through on-air satellite reception reports, with initial signal reports of **1 S-point above noise** for AO-40 beacons using a grid reflector, improving to **3-4 S-points above noise** with a 2-turn helical feed. The author references a _NanoVNA_ for impedance measurements and discusses the relationship between slot and dipole antennas in the context of patch design. DXZone Focus: Web Article | 70cm Patch Antenna | On-Air Satellite Reception | Circular Polarization

Picture taken from official manual with notes on tuning stubs for each band

TAPR, an international organization dedicated to amateur digital communications, is pleased to present this collection of information about TAPR, via the World Wide Web.

World Map - Time Zones realtime map allow to select and display current time for selected regions

Search K1N On-Line log

An ham radio contest log sheet in a PDF US letter printable format, can be used for portable operations, free to print and download.

Find out about the latest launch and mission to the Mir Space Station or Shuttle now consolidated in a single web site

IMO was created in response to an ever growing need for international cooperation of meteor amateur work. Radio Observations.

Rules of CQ World Wide RTTY Contest. The CQ World Wide RTTY DX Contest take place last full week-end of September, inviting amateur radio operators globally to connect across various CQ zones and countries. Participants will operate on five designated bands: 3.5, 7, 14, 21, and 28 MHz, exchanging RST reports and zone numbers. Scoring is based on QSO points multiplied by zone, country, and QTH multipliers. The contest encourages innovation in operating strategies while adhering to established rules to ensure fair competition among entrants.

The resource provides coaxial cable attenuation data, listing signal loss in dB per 100 feet for various cable types across a frequency range from 1 MHz to 5.8 GHz. The initial table details attenuation for cables such as _RG-58_, _RG-8X_, and RG-213, with impedance values of 50 ohm or 75 ohm, at frequencies up to 1 GHz. For example, _RG-58_ exhibits **0.4 dB** loss at 1 MHz and **21.5 dB** loss at 1 GHz per 100 feet. A subsequent table expands on this data, including LMR series cables like _LMR-400_ and LMR-600, along with other types such as 9913F7 and RG214. This section covers frequencies from 30 MHz to 1,500 MHz, also noting the outer diameter of each cable. For instance, _LMR-400_ (0.405" diameter) shows **0.7 dB** loss at 30 MHz and 5.1 dB loss at 1,500 MHz per 100 feet. The final section focuses on VHF/UHF/Microwave amateur and ISM bands, presenting attenuation in dB per 100 feet (and meters) for frequencies including 144 MHz, 450 MHz, and 2.4 GHz. This table includes larger diameter hardline options like 1/2" LDF and 7/8" LDF, in addition to flexible coaxial cables. For example, 1/2" LDF cable demonstrates **0.85 dB** loss at 144 MHz and 6.6 dB loss at 2.4 GHz per 100 feet. DXZone Focus: Coaxial cable attenuation | LMR-400 | RG-58 | 5.8 GHz

This online project guide details the construction of a homebrew boom microphone system. It details the assembly of a microphone shell from a 3/4" PVC pipe section and an end cap, requiring a drilled hole for a snug fit of the electret or condenser mic element. The internal wiring schematic specifies a **2.2 K** resistor and a **47 uF** polar capacitor for signal conditioning, with a circuit diagram provided for integration with IC-706 series transceivers. The guide outlines the use of CAT-5 cable for internal connections, incorporating strain relief at the rear of the mic shell, and an inline 3.5 mm jack to facilitate an external _PTT_ line, designed for a foot-mounted switch. Further construction involves fabricating a microphone shock mount from a 2-inch PVC connector, detailing the creation of four "fingers" and the insertion of screw-eyes for attaching elastic bands, which are twisted 180 degrees for tensioning and vibration isolation. A foam wind screen is also incorporated into the microphone assembly, secured with adhesive. The boom arm itself is repurposed from an articulated architect lamp, with the original lamp assembly converted into a **60 watt** resistive load for testing power sources. Microphone cabling is secured to the boom arm using wire ties, ensuring sufficient slack at hinge points to maintain articulation. The boom base is mounted to a bookshelf, requiring specific positioning to achieve proper microphone placement in front of the operator. Performance evaluation of the microphone system is conducted through on-air audio signal reports from other amateur radio operators. DXZone Focus: Online Project Guide | Boom Microphone Construction | Electret Mic Element | PTT Line

This web article details the construction of a 4-meter band coaxial dipole antenna, designed for operation between **70.000 MHz and 70.500 MHz**. The resource provides a bill of materials and step-by-step assembly instructions for a half-wave dipole constructed from _RG-58_ coaxial cable. The design specifies a direct 50 ohm feedpoint impedance, eliminating the need for an external matching network. Construction photographs illustrate the stripping and soldering processes for the coaxial cable elements, ensuring proper electrical connection and physical integrity. The article includes specific dimensions for the radiating elements, derived from calculations for the 70 MHz band. The project outlines the physical dimensions required for resonance at 70 MHz, with the outer braid forming one half and the inner conductor forming the other. The feedline connection is directly to the coaxial dipole's center, maintaining a 50 ohm characteristic impedance. While the article does not present SWR plots or VNA sweeps, it focuses on the mechanical construction and dimensional accuracy for achieving a functional 4-meter dipole. The design is intended for fixed station use, with no specific mention of polarization or height above ground, but implies a standard horizontal orientation for dipole operation. DXZone Focus: Web Article | 4m Coaxial Dipole | Construction Guide | 50 ohm Feed

Icom IC-7300 english brochure, technical specifications and product description

Simply work as many countries and CQ Zones as you can in each calendar year, regardless of the band or mode

A web site for those interested in ham radio Software Defined Radio (SDR). SDR Zone provide forums, reviews and user blogs relating to any type of SDR

STC, AWA, Valve Radio, Airzone, Kriesler, Mullard, Western Electric, dating Australian radios

DMR Contact Manager is a Free software package designed to make it easy to maintain channel, zone, contact and call group information in these radios. It is fully compatible with the Ham-Digital and RadioID database systems and allows instant codeplug updates from a wide variety of sources. DMR Contact Manager is designed for use with Connect Systems CS700/CS701/CS750/CS800/CS801/CS800D radios, as well as the Tytera MD-380/390/390GPS, TYT MD2017/MD9600, AnyTone AT-D868UV and AT-D858, Retevis RT3, and similar radios that use the RDT/RDB file formats.

Show CQ and ITU Zone in an interactive clickable map based on google maps. Additional locator tool tip can be displayed by clicking on points, and a search function it is also available to locate addresses, and locators.

A large CQ Zones World Map in Jpeg format.

Selecting appropriate coaxial cable and wire for demanding amateur radio applications, particularly those involving high power or harsh environmental conditions, is crucial for maintaining signal integrity and operational safety. This resource details Harbour Industries' specialized offerings, which include Mil-Spec and commercial designs such as NEMA HP3/HP4 and SAE AS22759, suitable for aerospace, military, and industrial sectors. Their product line addresses the need for robust conductors capable of withstanding extreme temperatures and mechanical stress, often encountered in antenna systems or amplifier interconnections. The company highlights its AeroPOWER® Firezone M25038/3 cable, specifically engineered for high-temperature environments like aircraft engines. This particular product exemplifies their focus on solutions for critical infrastructure where reliability under adverse conditions is paramount. Such cables are relevant for hams building or maintaining stations in challenging climates or those operating high-power amplifiers where internal wiring must endure significant thermal loads. Harbour Industries also provides a range of high-performance cables designed to meet stringent specifications. Their expertise in high-temperature and high-performance cable manufacturing positions them as a supplier for specialized wiring needs beyond standard off-the-shelf options, ensuring durability and performance for advanced amateur radio setups.

Announcement of the Icom IC-7610 during the Tokyo Ham Fair, August 20 2016.

HF/50 MHz 100W All Mode Transceiver. The FT-891 provides stable 100 W (25 W AM) high power output

Electric Fields, magnetic fields, electromagnetic fields, losses, fresnel zone, nearfield and farfield

Baofeng UV-5R dual band handheld transceiver, features, pictures, movies, links and manual.

The _DL4EBY_ resource page provides operational data for Earth-Moon-Earth (EME) communications on VHF, UHF, and microwave bands. It includes a 432 MHz and above EME Directory in ASCII and HTML formats. _K1RQG_ provides 432 MHz and up EME Net Notes. EME Operating Procedures were confirmed at the EME Conference 2002 in Prague. A lunar calendar from _DL7APV_ is linked via _G4CCH_'s pages. Resources for CW contest operation include the _PED411i.zip_ file. A "Cheat Sheet 432 & up" is available for EME operations. The _Dubus_ 70cm CW EME Activity Event is referenced for moonbounce activity. DXZone Focus: Operating Activity | Global | EME, CW | VHF, UHF, Microwave

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HamAlert let you receive Push,SMS,Email notifications for Cluster,RBN,SOTAwatch spots, with customizable filtering based on many criteria including DXCC, SOTA and WWFF references, CQ zones

Mircules HAM QuickLog provides a mobile logging solution for amateur radio operators, supporting quick contact entry on iOS and Android platforms. It features multiple log file management, instant callsign information display including Country, ITU zone, CQ Zone, and DXCC number, and robust ADIF and CSV import/export capabilities. The application is designed for efficient logging with optional fields and default values, streamlining the process for both shack and field operations. The software includes dedicated support for POTA, SOTA, and IOTA activations through specific fields like MY_SIG_INFO, SIG_INFO, MY_SOTA_REF, IOTA, and MY_IOTA. A specialized contest mode offers real-time dupe checking and automatic TX exchange updates to enhance contest efficiency. Integration with QRZ.COM and HAMQTH.COM allows for direct operator information lookup and import, while Open Street Maps integration provides geographic context for contacts. The application also features a notes and scratchpad function for each log file.

The Hentenna is an Asymmetrical Double Rectangle (ADR) Loop Antenna originally designed by Japanese Hams operating on the 6 m Band in the 1970s.