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

The **NW3Z** optimized wideband antenna designs, originally presented at Dayton 2001, detail Yagi configurations for the 20-meter, 15-meter, and 10-meter amateur radio bands. This resource provides access to the design files, likely containing critical parameters such as element spacing, element lengths, and boom dimensions, which are essential for replicating these directional antennas. The designs focus on achieving wide bandwidth, a desirable characteristic for contesters and DXers operating across a significant portion of each band. The content specifically references "nw3z-Antenna-DesignsDownload," indicating that the core information is available as a downloadable file, presumably in a format suitable for antenna modeling software or direct construction. Such files typically include **NEC models** or similar data, allowing for performance analysis and optimization before physical construction. The emphasis on "optimized wideband" suggests design considerations for SWR bandwidth and gain characteristics over a broader frequency range than typical narrow-band Yagis. The resource serves as a direct source for specific, proven antenna designs from a known amateur radio antenna designer, offering practical data for hams interested in building high-performance Yagi arrays for HF.

Standard diplexer design is based on singly-terminated Butterworth filters.

A homemade 16 foot falling derrick to tilt up a 50 foot high, 18 inch wide Glen Martin aluminum tower by N6RK

Cushcraft R5.pdf

An open source software defined receiver for Linux, Free DSP and Windows

2 element Yagi antanna plan from G3SYC

Tim Kirby IC-706 review of this small portable Icom transceiver

Kenwood TS-2000 Review

Download the PDF with USA Amateur radio HF band plan and common country prefixes updated in 2008 by Icom

VA3STL experience on reorganizing his shack and setting up a new random lenght wire antenna for his Yaesu FRG-7 receiver

ADIF Master is a Windows program for working with amateur radio log-books. ADIF Master convert Cabrillo, TR, CT logs or a part of it into an ADIF file. Also you can use ADIF Master to open and edit ADIF log files using filters, add and remove or modify ADIF tags and entries

Halo antenna for 4 meters band with dimensions, pictures and assembling instructions

A small multiband antenna for vacation in french

Design your own folded dipole antenna

Quagi antenna design, this little windows application let you calculate dimensions of elements and spacing of a quagi antenna. Freeware by VE3SQB

Antennas, books, rf parts, tubes,connectors and cables and many accessories at RF parts.

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.

W3FF article about the buddistick portable vertical antenna in a PDF file

The Adcock antenna has been used for a long time for RDF. It is basically an interferometer.

Antennas, base mobile scanner and vhf antenna, coax cables, coax switch, Lightning Arrestor, mounts, power supply, speakers and wattmeters

A woktenna. The collector and stand collapses in seconds, is aimable, portable, and gave terrific gain. This is a great little setup for a laptop on the go trying to get the distant wifi access.

"Sells high voltage film and electrolytic capacitors for antique tube radios. Carries 630 volt metal-film, metallized and mylar film capacitors as well as electrolytics. Also has ""capacitor"" tips for antique radio restorations."

Argo, developed by I2PHD and IK2CZL, functions as a specialized freeware viewer for various weak signal modes, specifically MTHELL, Slow CW, QRSS, and DFCW. It processes audio input to visualize and decode these extremely low-speed transmissions, which are often imperceptible to the human ear. The software's capabilities extend to EME (Earth-Moon-Earth) operations, where its sensitivity to weak signals is particularly advantageous for detecting faint lunar reflections. The application provides a visual representation of the received signals, allowing operators to discern patterns and decode information from signals buried deep within the noise floor. Its design focuses on extracting data from signals with very narrow bandwidths and long integration times, characteristic of QRSS and similar modes. This tool is distinctively useful for experimenters and DXers engaged in challenging weak signal communication, offering a dedicated platform for modes not typically supported by general-purpose digital mode software. Its specialized focus on _Slow CW_ and _MTHELL_ makes it a niche but effective utility for specific operating scenarios.

OZ2OE Technical pages, a 3 element 28 MHz light weight Yagi for 10 meters band

What is the best WiFi antenna for me? Looking for a range extender antenna for your WiFi system. This article will help in choosing the correct antenna for your system

Manufacturer of communications antennas, bandpass filters, RF combiners, receiver multicouplers, diplexers, duplexers, RF connectors, RF circulators, RF isolators, RF couplers and SWR meters

A 6 meters band amplifier width schematics

Schematics and plans to build a custom CAT and audio pc interface

X-Beam antenna by K0EMT for 50 Mhz and VHF UHF bands

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

10 Meter WonderBar Antenna, present an SWR 1:1 over entire band, great DX, rotateable by hand, 8 ft long - build for about $20

Isotron antennas are low-profile HF antennas. If you need a small antenna, then an Isotron may be the answer. Bilal isotron antennas.

The K5OE 2-meter vertical mobile antenna design, detailed in this resource, employs a 3/8-wavelength vertical section complemented by four shortened radials, forming an off-center-fed vertical dipole. This configuration creates a self-contained lower half, enhancing efficiency compared to traditional 1/4-wave monopoles relying on vehicle bodies for a ground plane. The article specifies construction using PVC components, 10-gauge insulated wire for elements, and provides precise dimensions in both inches and centimeters for the 25-3/16" (64 cm) vertical and 7-3/16" (20 cm) radials. Performance data indicates an honest 3 dBi of gain at 6 feet elevation (2 dBi free-space), with a pattern favoring the horizon, suitable for Low Earth Orbit (LEO) satellite communications. At 20 feet high, the same antenna exhibits almost 6 dBi of gain, with a nominal 50 Ohm feedpoint impedance at 146.850 MHz. Tuning instructions involve trimming element lengths, with the author achieving a 1.2:1 SWR by pruning the mast to 24-3/4" and radials to 7". The resource highlights the antenna's effectiveness for mobile LEO satellite uplinks, particularly at low elevations, and its suitability for fixed, mobile, or portable operations. The flexible wire elements allow for easy folding, making it a practical choice for backpacking. The original design by K5OE was previously hosted on aol.com.

RTTY Tutorial by K4WW, foundamentals, FSK and AFSK

A dead easy 50 mhz preamp by VK3CJS

Macintosh automatic position reporting system, developed by Bob Bruninga, WB4APR, to track boats and vehicles using GPS and packet radio. MacAPRS was written by Keith Sproul, WU2Z and Mark Sproul, KB2ICI

An interesting article on NVIS antennas, explaining basics of NVIS antennas and the main usage of this particular aerials by Patricia Gibbons

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.

If you have a small lot and want on 160 meters this is our version of the antenna by K5CBL Troy

Indoor wire antenna for 7 mhz from F6CYV

KaWin is a legacy digital RF data communications program designed to harness the full potential of Kantronics Terminal Node Controllers (TNCs) via their proprietary Host Mode. Serving as a central hub for the digital shack, it gave operators running packet radio or DX clusters a native graphical interface to seamlessly manage RF traffic across up to four simultaneous TNCs. The primary limitation today is extreme software obsolescence. KaWin is a completely unsupported, discontinued product running exclusively on legacy operating systems, peaking at Windows 95. Modern shacks cannot run it natively; it strictly demands antiquated hardware like physical RS-232 serial ports with 16550 UARTs, dedicated IRQ assignments to prevent RX/TX buffer overruns, and specific legacy TNC firmware EPROMs. Despite being a relic, its benefits for the dedicated digital DXer were substantial. By fully exploiting Kantronics Host Mode rather than basic KISS configurations, it maximized on-the-air throughput and station efficiency. For retro-computing hams restoring vintage packet stations, KaWin still provides a robust environment that successfully bridged raw RF data routing with a highly functional, multitasking graphical user interface.

The resource details the construction and performance of a dual-band 40/30 meter _Moxon_ antenna, evolving from an initial single-band 30-meter design that failed in a storm. It specifies materials such as four 10-meter fishing rods, galvanized iron TV antenna support pipes, 1mm diameter PVC-covered copper wire, and a piece of 75-ohm TV satellite cable for feedline. The document outlines the iterative design process, including initial resonance measurements of 9.9 MHz for 30 meters and subsequent recalculations to shift the center frequency by 300 kHz using _Moxon software_. Initial testing on a roof yielded SWR readings of 1.4:1 at 7.200 MHz and 1.5:1 at 10.280 MHz. After installation atop a 30-meter tower, the final SWR measurements were 1.1 at 7.130 MHz and 1.4 at 10.230 MHz, with a notable 30 dB front-to-back ratio on 40 meters. The 30-meter performance, while good, showed a front-to-back ratio of approximately 15 dB, suggesting a slightly high resonance. The antenna's placement on a 700-meter hill, with a significant ground drop in certain directions, is noted as a potential factor in its excellent DX performance, enabling daily contacts with the USA West Coast on 30 and 40 meters with 100 watts.

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.

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.

adsbScope is a freeware Windows application designed for processing _ADS-B_ (Automatic Dependent Surveillance-Broadcast) frames received from a compatible decoder. It identifies aircraft, calculates their real-time positions, and presents flight parameters in both alphanumeric tables and a graphical display. The software interfaces via a virtual COM port, receiving raw frames to provide detailed situational awareness, including a global coordinate grid, continental coastlines, over 4,000 **airport** locations, and major cities. Users can overlay OpenStreetMap tiles and view world state boundaries, with each tracked aircraft rendered with labels showing altitude, speed, heading, squawk code, and flight identifiers. When paired with the adsbPIC-decoder, adsbScope enables advanced hardware control, allowing users to toggle data filters for specific frames like DF17/18/19, adjust analog signal thresholds for reception fine-tuning, and manage system resets or bootloader activation directly from the PC. This functionality provides a customizable toolkit for hobbyist radar listeners, offering a robust alternative to commercial tools for processing aircraft data. The software displays up to **1090 MHz** transponder data and can track aircraft up to 250 nautical miles.

Automatic Antenna Tuners. Kits and assembled. Other station accessories

PA0FRI's "S-MATCH ATU" published in RSGB's RadCom March 2003). The Balanced Universal ATU Photographs of ZL2ML's S-Match were added.

A project by DL5DBM for a VHF UHF antenna suitable for handheld transceivers

Excellent article on limiting noise using chockes by Chuck Counselman, W1HIS