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This version of the broadband hexbeam is based on the work of Hunt G3TXQ, HB9MCZ, and Shoemaker K4KIO. EZNEC model is based on a wider element spacing than the version published in QST by K4KIO

Javascript filter design page with introduction to low pass filters by k7mem

The document explains the technical aspects of how the Internet Radio Linking Project (IRLP) works, focusing on the use of VoIP streaming software under the Linux operating system. It details the audio sampling, compression, transmission, reception, and playback processes involved in IRLP communication.

Reviews of two types of poles used on portable operation to support wire antenna and accessories to plant poles in the ground by N4KGL

Long review of the Elecraft K3 , 18 months on.

Such kind of omnidirectional antenna gives the possibility to be QRV with horizontal polarisation, as commonly used for the CW and SSB section of the 2m band. This actual design shows a 1.3:1 bandwidth of about 150kHz, centered to 144.200MHz.

How do we make an HF station work more effectively? Antennas are the key!

Resources for custom battery chargers and power supplies from powerstream

Article on a QRSS receiver for 30 meters band

The Superantennas MP-1 portable HF antenna is analyzed for its design and field performance, particularly its high-Q loading coil and 3/8-inch mounting. The review details the antenna's construction, including an 8-inch vertical section, a large-diameter loading coil tuned by a sleeve, and a 4-foot whip that disassembles into six rods for transport. Initial testing with the supplied 10-foot ribbon cable "ground plane" yielded poor SWR and RF hot conditions, indicating an inadequate ground system. Further experimentation with longer radials and resonant counterpoises for each band improved matching and eliminated RF hot issues, but introduced significant operational complexity. The author notes the difficulty in optimizing both counterpoise length and coil setting without an antenna analyzer, and the sensitivity of the MP-1 to counterpoise deployment. The review also discusses the recommendation to tune for maximum received signals rather than minimum SWR, often necessitating an external ATU due to the antenna's typical low impedance. The **MP-1**'s critical dependence on resonant counterpoises for effective operation, especially when elevated, is highlighted as a major drawback for portable use. The author ultimately sold the antenna, concluding that despite its sound technical design, its fussy nature and the need for extensive counterpoise management or an ATU detract from its portability and convenience compared to simpler, less expensive dipole solutions. The **Superantennas MP-1** is deemed a flawed portable antenna, requiring considerable effort to achieve its claimed performance.

Win32 command line utility, that allows you to create Master Callsign Database file (DTA), used in many contesting programs, from different logs in ADIF, Cabrillo, and plain text formats.

This resource, intended to present historical score records for the _ARRL International DX Contest_, currently displays a "Page not found" error. The page's original purpose was to document top scores and records for both Phone and CW segments of the contest, offering a historical perspective on competitive amateur radio operating. Without the content, no specific technical details regarding past contest results, callsigns of record holders, or score breakdowns can be extracted. The resource's current state prevents any analysis of score comparisons, operational strategies of top stations, or the evolution of contest performance over time.

A 70cm ground plane antenna made with a 90cm of 1mm silver steel rod

L4B by Drake amplifier mod

The Orion II A9 Power Distribution Board Problem and Fix by N6IE

Pictures, details and specifications about Yaesu VX-170

A borderline insane 30m QRSS beacon project, completely independent of computer control and containing NO microprocessors!

DF9CY using Softrock RTX on 50 MHz

GUI for the KK7KA Wolf software, that was originally written as command line interface only. Wolf is a weak signal software

Influence of the ionosphere on the EME signals by EAVQ

This Power meter is capable of dissipating up to 100 watts for a short period and 20 watts continuously

Fixing notice subtle distortion on SSB receive audio on the Yaesu FT-1000D

VE3VN describe in this article how to raise a tri-band yagi antenna onto a DMX-52 tower with pictures and schemas that cover the whole raising process.

Build this noise reducing system to enhance audio of your speaker. A project by kg4jjh

HF Radio Preselectors,BCB filters,Low Pass filters,Band Pass filter

Saipan rental shack for the customer who enjoys amateur radio from Saipan

Schemaric for a simple headset adaptor for some popular HTs by Kenwood, Baofeng and Wouxun by N1GY

Materials, installation, inspections and certification

Some notes on double-shielded coaxial cable

Yaesu ATAS 120 Autotune Antenna Repair

How manage and quantify ground loss in vertically-polarized antennas by VE3VN

Configuring the TM-D710 with Garmin Nuvi 350 for APRS setup

N5KGL interesting article on portable antennas. Greg report his experience on using several types of portable antennas.

How to establish a APRS local gateway from Internet to Radio with a TM-D710 and UI-View, the well known software from G4IDE

Passive Band-Pass Filter, low-pass filter calculator

This article was first published in CQ-TV issue 208. Author try to explain digital television in layman's terms and without getting too involved in mathematics.

Display and Send Hellschreiber On Your iPhone and iPad - iPhone / iPad app to send and receive Hellschreiber

Linear amplifiers cold adjustments with network analyser (VNA)

A simple, cheap and easy to build 26 feet long vertical antenna that works DX on 20 - 10 meters including WARC Bands, it is designed for portability for field days, camping, or permanent installation, cost, and to achieve at least 1/2 wavelength on the WARC bands.

Christoph Petermann DF9CY DRM demonstration receiver project including Circuit Diagram and component list

QSL collection from F5RRS

Original article was in December, 1986 QST

In this article you can find solutions to the problem of keeping your ham radio antennas hidden from the CCR Police

160-10 Meters 1500 Watt Amp - W4NFR

The article, "Using 75 Ohm CATV Coaxial Cable," details methods for employing readily available 75-ohm CATV hardline in standard 50-ohm amateur radio setups. It addresses the inherent impedance mismatch and practical considerations, such as connector compatibility, for hams seeking cost-effective, low-loss feedline solutions. The resource specifically contrasts common 50-ohm cables like RG-8, RG213, and _LMR-400_ with 75-ohm hardline, highlighting the latter's lower loss characteristics, particularly at VHF and UHF frequencies. It explores two primary approaches to manage the impedance difference: direct connection with an acceptable SWR compromise and precise impedance transformation. The direct connection method acknowledges that a perfect 1:1 SWR is not always critical, especially when using low-loss coax. For impedance transformation, the article explains the use of half-wavelength sections of coax to reflect the antenna's 50-ohm impedance back to the transmitter, noting its single-frequency effectiveness. It also briefly mentions transformer designs using toroid cores and a technique involving two 1/12 wavelength sections of feedline for broader bandwidth. The content further clarifies the concept of _velocity factor_ for calculating electrical versus physical cable lengths, providing a generic formula for precise length determination. It notes that while half-wave matching is practical for 10 meters and above, it can result in excessively long runs for lower bands like 160 meters, potentially adding **250 feet** of cable. The article also mentions achieving a usable bandwidth of 28.000 MHz up to at least **28.8 MHz** on 10 meters with specific transformation techniques.

Home Brew 6 Meter Amplifier with a single 4CX250B by W4NFR

Simple Elecraft KX3 and PowerSDR configuration by AG1LE

A 50 MHz homemade RF spectrum analyzer

Over 70 distinct contest rules are cataloged, including major events like the _ARRL DX Contest_, _CQWW DX Contest_, and numerous state QSO Parties, providing direct access to official guidelines. The resource also compiles contest calendars from sources such as _WA7BNM_, ARRL, and _LA9HW_, offering a centralized hub for upcoming operating activities. Historical contest records are detailed for various events, including _ARRL 10 Meter Records_ for W/VE and DX, _CQWW DX Records_, and _ARRL Sweepstakes_ results by K5KA. This compilation allows operators to review past performance and understand competitive benchmarks across different bands and modes, aiding in strategic planning for future contests. The resource serves as a practical reference for both casual participants and serious contesters.

G0KYA MMANA-GAL presentation and samples