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Indoor multiband dipole with EZNEC data files for simulation and analysis. Includes details on construction, tuning, SWR plots, and software usage. This page includes two different dipoles, a first version for 20-10 meters and an extended version covering 40-10 meters allowing a full coverage of most used ham radio HF Bands.

Repeaters, transmitters and receivers manufacturer for ham radio and commercial applications

Article by John C. McGrath W9JCM

A very interesting and informative introduction to the 50 MHz band, also known as 6 meters or better the Magic Band, by Dave Finley N1IRZ, covering different propagation modes, operating experiences, and the excitement of the band. The content provides insight into the unique characteristics of six meters and its unpredictability in signal propagation.

The R.F. Connection Specialist in RF Connectors, Coax, Cables, Grounding

Create Online Maps, Check Forcasts and Conditions, more features being added each month, by hfradio.org

S Meter Lite is a no-cost program that displays your receiver's S Meter signal strength in a window by W8WWV

Table of allocation of international Call Sign series

This page describes the loading coil (inductor) that W8WWV built for my center-loaded 160 meter band (1.83 MHz) vertical antenna.

EchoStation is a commercial windows repeater-control program for Windows which makes it easy to set up a complete, fully-functional repeater or announcement machine using a personal computer. Demo version available

A 10-meter J-Pole antenna, detailed in QST February 1950, offers a straightforward solution for hams operating with restricted space. This design, originally presented by W1BLR, is a **half-wave radiator** fed by a quarter-wave matching stub, providing a low-angle radiation pattern beneficial for DX. The article describes building the antenna from readily available materials like copper pipe, emphasizing its simplicity and effectiveness for **single-band operation**. The J-Pole's inherent design provides a good impedance match to 50-ohm coaxial cable without the need for an external tuner, a significant advantage for portable or minimalist stations. Its nondirectional pattern ensures coverage in all directions, making it a versatile choice for general operating on the 28 MHz band. The construction plans are clear, allowing even those with basic workshop skills to assemble a functional antenna.

Cat interface for Kenwood transceivers, tested with TS-850 and kenwood TS-50 but should work with all Kenwood rtx

There are many ways to support an amateur radio antenna. Installatio of a utility pole will provide an antenna height of approximately 13 meters (40 feet) and will require no guy wires.

The document is a PDF detailing the construction of the DBJ-1 VHF-UHF Dual Band J-Pole antenna for amateur radio use. It provides instructions on how to build a high-performance dual band base antenna for VHF and UHF bands using a single feed line for less than $10.

IR-DX HQ website

Excellent guide to using ferrite cores for interference suppression. Understanding and Solving RF Interference and Noise Problems by Jim Brown K9YC Audio Systems Group, Inc. PDF File

Version 1.4.6 of _AAVoice_ functions as a digital voice processor for amateur radio, designed to operate on Windows platforms from 9x through 10. This software leverages pre-recorded WAV files for transmission, allowing operators to send pre-defined messages or calls efficiently. Its core functionality includes PTT control, which can be managed through a simple circuit connected to a COM port, providing a reliable interface for radio keying. The program offers extensive macro capabilities, streamlining repetitive transmissions during contesting or DXing. It also features direct integration with the _AALog_ logger, enhancing workflow for those using DXsoft's suite of tools, and can interface with other compatible programs via its COM-interface. Author Alexander Anipkin designed _AAVoice_ to require a working sound card, and it comes with a basic set of sound files. Users can easily create additional WAV files using standard Windows sound recording utilities, ensuring flexibility in customizing audio content for various operating scenarios.

The ZS6BKW multiband HF antenna, a design by ZS6BKW (G0GSF), functions effectively on multiple HF bands without requiring an Antenna Tuning Unit (ATU) for 40, 20, 17, 12, 10, and 6 meters. This antenna, approximately **27.51 meters** (90 feet) long with a 12.2-meter (40-foot) open-wire feeder, is a direct descendant of the _G5RV_ but offers superior multi-band resonance. It can be deployed as a horizontal dipole or an inverted-vee, with the latter requiring only a single support and maintaining an apex angle of at least 90 degrees to prevent signal cancellation. Performance data, recorded with an MFJ Antenna Analyser, indicates SWR values of 1:1 on 7.00 MHz (40m) and 14.06 MHz (20m), with SWR below 1.3:1 on 17m, 10m, and 6m. While primarily designed for these bands, the antenna can be adapted for 80m, 30m, and 15m with an ATU, preferably at the balanced feeder's base. The use of 450-ohm twin-lead for the feeder is recommended over 300-ohm for improved strength and reduced losses, especially in adverse weather conditions. This design, originally published in _RadCom_ in 1993 and featured in Pat Hawker’s "Antenna Topics," provides a compact and efficient solution for HF operation, particularly for those with limited space or resources.

The radio spectrum in usa, PDF File representing the united stares frequency allocations in graphical mode, dated 2003

Downloadable DOS program for propagation prediction for the serious contester.

DXMaps.com presents a dynamic, real-time mapping service for amateur radio DX spots, integrating data from traditional DX clusters, _PSK Reporter_, and WSPR networks. The platform visually plots global QSO and SWL activity, enabling users to observe propagation conditions across various bands, from 2200m to >450 MHz. It offers distinct overlays such as the magnetic equator, gray line, moon footprint for EME, and VOACAP propagation predictions, providing a comprehensive view of radio wave behavior. The service allows granular filtering of displayed spots, including options to show only DX-Cluster data, PSK Reporter activity, or WSPR signals. Users can refine the map view by selecting specific bands (e.g., 160m, 20m, 6m, 2m), limiting spots to the last 15 minutes, or displaying only contacts exceeding **2600 km**. Additional features include the ability to toggle grid squares, aurora forecasts, and various amateur radio zones (CQ, ITU). Distinctively, the resource updates automatically every minute, ensuring current propagation intelligence without manual refresh. It also supports specialized views for EME, ionospheric scatter, and aircraft scatter, alongside FM DX and APRS activity. The platform emphasizes the importance of accurate locator information in DX spots to enhance data quality and offers a user manual and FAQ for guidance.

This page explains how to construct high-Q inductor coils.

Balcomy antenna modification to cover top bands, by Harry Lythall SM0VPO

A free to download and print, amateur radio station log sheet in a paper US letter format

G4NCE's illustrated vintage military wireless collection. Featuring British, Canadian and New Zealand Army eqpt, and Royal Air Force eqpt, from WW2 and the 1950's.

Software to train reading Morse code or software to run CW mode or even COHERENT CW mode on your amateur radio equipment from your PC.

Illustrates the fundamental principles of radio repeater operation, detailing how different duplex configurations overcome signal limitations in varied terrains. It begins by contrasting _simplex_ communication, where all units share a single frequency, with more complex systems designed for extended range and specialized applications. The resource systematically presents each mode, from basic base station setups to advanced multi-frequency configurations. The content specifically covers hemi-duplex systems, often used in commercial dispatch, where the base station transmits on one frequency and mobiles on another, without rebroadcast. It then progresses to semi-duplex repeaters, the most common type in amateur radio, which automatically retransmit received signals on a different frequency. The explanation extends to demi-duplex and hemi-demi-duplex systems, which incorporate multiple control links for enhanced operational flexibility and secure communications, as seen in public safety applications. Finally, the resource clarifies full-duplex repeater systems, exemplified by cellular networks, where simultaneous two-way communication is achieved through distinct transmit and receive frequencies for each direction. The visual aids, including **9 distinct figures**, effectively demonstrate the signal paths and frequency assignments for each operational mode, providing a practical understanding of repeater architecture.

Stacking and phasing HF and 6m arrays antenna switches and contesting devices. Custom low band antenna arrays, bandpass filters,commercial/Mil STd filters,microwave components, commercial broadcast filters.

Also known as G5RV junior the half size G5RV feature reduced dimension and multiband coverage

Sharing beverage antennas with this switch boxes is possible. This article describes a 6-position remote antenna switch for Beverage antennas on 3 bands (160m, 80m, 40m). It allows selecting one of 6 antennas for each band without affecting other receivers. The system uses a control box with a rotary switch and a separate splitting box with bandpass filters for each band.

How to make a Weatherproof Vertically Polarised Omnidirectional Aerial, The Slim Jim Antenna

Thierry LOMBRY, ON4SKY, develops in three long articles all you need to know about amplification, and how to seletc an HF and a solid-state amplifier, with pictures.

Presents the product lines and corporate information for Japan Radio Company (JRC), a long-standing manufacturer of radio communication equipment. The company's offerings span various sectors, including marine, land, and aviation communication systems, alongside their historical contributions to amateur radio with notable **HF transceivers** and **shortwave receivers**. JRC emphasizes its technological expertise in areas such as radar, satellite communication, and network solutions, contributing to global safety and security infrastructure. The resource details JRC's commitment to leveraging its accumulated knowledge and experience in information and communication technology. While the primary focus has shifted towards commercial and governmental solutions, the legacy of JRC's amateur radio products, such as the JRC JST-245 transceiver and the NRD-525 receiver, remains significant within the ham radio community, known for their robust build quality and performance.

F6EZX presents a detailed account of constructing a compact, multi-band _Levy antenna_ for portable holiday operations, specifically addressing issues with local QRM from a previous _Deltaloop_ setup. The article outlines the design criteria, including multi-band operation on 40m, 30m, 17m, 15m, 12m, and 10m, a symmetrical configuration to reduce interference, and a low take-off angle for DX. Construction involves 2x 10.3m radiating elements and a 15.3m open-wire feeder (ladder line) with 7cm spacing, made from 1.5mm2 copper wire and foam pipe insulation spacers. Theoretical calculations, referencing F9HJ's "_Les antennes Levy_" book, guide the determination of element lengths and feeder impedance characteristics, aiming for a good match across bands with a commercial antenna tuner. Initial field tests with the _VCI Vectronics VC300DLP_ tuner showed a 1:1 SWR from 80m to 10m, with some difficulty on 17m. The antenna, mounted as a 45-degree slopper with the high point at 12m, successfully facilitated DX contacts to South America, particularly Chile and Argentina, suggesting a lower take-off angle compared to the previous Deltaloop which favored Brazil. The Levy antenna significantly reduced TVI/RFI, attributed to its improved symmetry and greater distance from the QRA. While signal reports on 15m and 20m were 1-2 S-points lower than the Deltaloop, its performance on 40m and 30m was comparable, fulfilling the design goals for a portable, low-cost, multi-band solution.

A simple multi-band magnetic loop antenna designed for 20, 30 and 40 metres, made from 16 feet of RG58 coax cable. The performance is impressive for its size but not meant to replace a Yagi. The antenna features a tuning head, matching unit, tuning capacitors, band change switch, and matching transformer. The feedpoint is at the bottom of the loop. The document provides detailed instructions on assembly and operation.

Excel spreasheet that calculate virtually every transmission line parameter that one may need. Include Length conversions, Reactance and Length of Stubs

A rotary trapped-dipole for 17 and 20 meters, as described by IZ7ATH, presents a practical solution for multi-band HF operation. The author, Talino, recounts his experience building this antenna for IK7ZCQ, detailing the evolution from an initial concept involving a grounded-driven element and gamma-match to a direct-fed, non-grounded design. His pragmatic approach, adapting available materials, is evident throughout the construction narrative, particularly with the use of eight tapered aluminum pipes for the driven element. Construction specifics include precise measurements for the aluminum tubing, with diameters ranging from 30 mm down to 16 mm, and a critical note on reducing tip thickness for weight optimization. The _traps_, initially a concern, are fabricated using 8 turns of RG58 coax on a 27 mm support, tuned to resonate at 18.1 MHz using a dip-meter. Talino emphasizes sealing the traps with RF glue and PVC tape to prevent water ingress, a crucial step for longevity. Field test results, conducted on a 10-meter pole in a clear garden environment, showed an SWR of 1.2:1 on 17 meters and 1.5:1 at 14.200 MHz. While SWR varied slightly when installed at Mario's QTH due to nearby objects, the antenna's performance remained commendable. The final half-dipole length is 46 cm for the 18 MHz tips, and the total weight is under 6 kg, with potential for further reduction.

Announced dx operations by By Bill Feidt/NG3K

This is a propagation prediction program tailored to the serious contester

Why Packet Radio? Could be, You are Missing Something Funm, by Greg Jones, WD5IVD

French manufacturer (F5MSU) of antennas and accessories since 1999 : Yagi, Delta-loop, dipoles, T2FD, verticales, EFHW, baluns, ununs, etc.

The page provides detailed instructions on how to build a double bazooka antenna for the 40 meters band. It includes information on materials needed, measurements, and assembly steps. The antenna can be configured as an extended dipole or an inverted V, offering low noise, wide bandwidth, and a 1:1 standing wave ratio. The content also offers calculations for other bands and includes photos of the antenna fabrication process.

You will find on these pages my experiences and results on antennas and local/non-local QRM/noise reduction. Using a broadband vertical active magnetic loop and a home made / designed broadband amplifier. Two vertical magnetic Alford loops are used in an array. Analog and Digital Signal Processing and a dual phase coherent Software Defined Radio (SDR) are used. By PA0SIM

Presents G0GSF Brian's ZS6BKW antenna, a refined iteration of the classic G5RV, offering improved performance across multiple HF bands. The design emphasizes specific radiator and ladder line lengths to achieve lower SWR on 40m, 20m, 17m, 12m, and 10m, making it a practical choice for operators seeking a single wire antenna solution. The document includes critical dimensions for the flat-top and the 450-ohm ladder line section, which are key to its multiband resonance characteristics. Unlike the original G5RV, the ZS6BKW aims for direct 50-ohm feedpoint impedance on several bands, reducing the need for an external antenna tuner. My field experience with similar optimized dipoles confirms that precise construction, particularly the ladder line length, is paramount for realizing the intended SWR benefits. This design offers a compelling alternative for hams with limited space or those preferring a less complex antenna system.

Listen to the DSTAR Repeater from Florida USA currently connected to Reflector 1c

Modification to the Bearcat 210 scanner for reception of 137 Mhz FM is a fairly simple process.

V26B Superstation available for rent. Click the link "information about renting the V26B station" for more information.

RTTY SSTV PSK31 MFSK MT63 PACKET APRS and more...

These pages provide general propagation advice for HF communicators. Information available includes inferred global propagation conditions, real time HF fadeout coverage charts, regional ionospheric vertical MUF maps and Hourly Area Prediction charts for Astralia and Asia, Europe and North America

Demonstrates a **DX cluster** web service providing real-time amateur radio spot reports, propagation information, and solar data. The platform integrates features such as a gray line map, **DXCC** tracking, and a personal logbook, allowing users to manage their confirmed entities and contacts. It supports various bands from 160m to 70cm, including specific filters for modes like FT8/FT4, and offers both web and Telnet access for spotting and monitoring. The service provides graphical representations of spot reports, detailing activity across different frequency bands and modes (CW, SSB, digital). Registered users gain access to advanced functionalities, including personalized filters and tools for calculating DXCC status. The platform also includes a classifieds section and options for mobile access, catering to a broad range of amateur radio operators interested in DXing and contesting.