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The Yaesu VL-1000 Quadra HF Linear amplifier

This sketch will read RF power and SWR from any SWR bridge, designed to work on VHF UHF bands

2 m. Band VHF Collinear with 2 Dipoles by sv1bsx

A program to control a repeater using an old computer and printer or serial port.

Long range Wi-Fi antennas you can build. Helicals, parabolics, and biquads discussed. How to add external antennas to WUSB54GC and F5D7050 usb wireless adapters for long range connections.

2 element Quand antenna for 10 - 12 - 15 -17 - 20 meters band

How to build an Hexagonal antenna in 3 hours

Download JT65-HF Amateur Radio software for reception/transmission of JT65A protocol with an emphasis upon its usage in the High Frequency Amateur Bands. This is the W6CQZ version not developed anymore.

An informative page about delta loop antennas

WSJT-X, a creation of K1JT, offers specialized digital protocols meticulously optimized for challenging propagation paths such as EME (moonbounce), meteor scatter, and ionospheric scatter. This software excels at VHF/UHF frequencies, and also provides robust performance for LF, MF, and HF DXing, enabling contacts far below the audible threshold. The program decodes signals from ionized meteor trails and steady signals more than 10 dB below the audible threshold, a testament to its advanced digital signal processing. It integrates nearly all popular features from its predecessors, WSJT and WSPR, while adding comprehensive rig control and numerous other enhancements for the serious weak signal operator. Available for Windows, Linux, and Mac OS X, WSJT-X is an open-source project, allowing hams worldwide to download the latest versions and engage in cutting-edge weak signal communication.

Modified version of the Telerana antenna which was orginially featured in the July 1979 issue of QST. The array is suspended within a framework made of fiberglass poles emanating from a central hub with the ends tied together with light weight rope around the perimeter. 10-15-20-30-40 meter band coverage

Article by Ed WE6W on a double bazooka antenna

40 meters band Delta loop antenna plan that is vertically polarised

ZZ Wave Net is a 40 & 80 meter full wave loop designed to fit on a city lot. ZZ Antenna is a folded dipole bent into an inverted V loop

What is the best balcony antenna? what antenna would you recommend for use on typical hotel balcony? Read some answers here

Notes on making the W2DU choke balun by placing several ferrite sleeves around a coaxial cable.

Free german Open Source HAM Logging Program unter the terms of the GNU General Public License. CLLOG runs under MS-DOS (Windows DOS-Window under 3.x,9x,NT,ME,2000) and LINUX. All Functions for Logbook.

Build a PSK-31 PC interface for the yaesu FT-817

Starting from an original project for a 2 element quad antenna for six meter band, ve7ca presents the dimensions for a 3 element version.

The project details modifications to an ARK-40 QRP CW transceiver kit, specifically replacing its original thumbwheel frequency selectors with a **BASIC STAMP BS-II microcontroller** and an optical shaft encoder. The redesigned control circuitry outputs a BCD code to the ARK-40's synthesizer, enabling more convenient knob-type tuning. This modification significantly alters the user interface, moving from discrete frequency selection to continuous tuning. Operating frequency is presented on an LCD readout, offering two distinct display modes: a "bandspread dial" mode that simulates an analog dial scrolling across the display in 1 kHz increments, and a conventional digital readout with 100 Hz resolution. Pushing the main tuning knob toggles between these modes, providing both rapid band traversal and fine-tuning capabilities. The software for the BASIC Stamp is written in P-Basic, addressing the challenge of accurate analog dial simulation. Physical modifications include fabricating a custom PC Board for the STAMP, mounting it with an L-bracket to the optical encoder, and creating a new front panel. The front-mounted speaker was relocated to accommodate the new tuning knob and display, transforming the **ARK-40 transceiver** into a more user-friendly rig with its built-in CW keyer and 5 watts of power.

A very quick and easy way to get on the air is to build a "Michigan Mighty Mite" CW transmitter for 160, 80, 40 or 30 meters. It can't get simpler than this. It has very few parts, costs almost nothing, and it works! Cost estimate $10 by VE6WTF

The resource provides detailed information about a five-band indoor magnetic loop antenna designed for amateur radio operators. This antenna is capable of operating on the 20, 17, 15, 12, and 10 meter bands, making it a versatile choice for various HF communications. Constructed from a single 3-meter length of 22 mm copper tube, the design emphasizes compactness and efficiency, which is particularly beneficial for operators with limited space. The page includes insights into the construction process, tuning, and operational tips, catering to both novice and experienced users. In addition to the technical specifications, the resource also discusses the advantages of using a magnetic loop antenna indoors, such as reduced interference and improved performance in urban environments. It serves as a practical guide for those interested in building their own antenna, offering a straightforward approach to antenna design and construction. Overall, this resource is a valuable addition to the toolkit of amateur radio enthusiasts looking to enhance their station with an effective indoor antenna solution.

This antenna modification is for the IEEE 802.11b networking protocol that operates at 2.4 GHz. It can be scaled easily to the 5 GHz frequency used by IEEE 802.11a by simply scaling the dimensions on the feed can and the excitation antenna to 2.4/5 = 48% of the dimensions shown above.

This page details the construction of a biquad antenna. The biquad antenna is easy to build, and provides a reliable 11dBi gain, with a fairly wide beamwidth.

Here you will find information about wire antennas as well as directional beams.

N3ox 6 meter moxon rectangle, pictures and assembly notes

Based on Motorola MRF454, schematics and component list

DJ9BV yagi antenna for 2 meters band

Presents a catalog of **QRP** transceivers, antenna tuners, and related accessories for amateur radio operators. The product line includes the ZM-2 antenna tuner, designed for efficient impedance matching across HF bands, and the NW-series QRP transceivers, offering low-power CW operation. Additionally, the site details various ladder line insulators and specialized connectors, emphasizing robust construction for field deployment and home station use. Each product listing provides specifications, operational parameters, and pricing information. Compares the features of different **QRP transceiver** models, such as the NW-40 and NW-20, highlighting their respective band coverage and power output capabilities. The ZM-2 tuner's performance is detailed with typical SWR reduction figures for various antenna types, demonstrating its utility for portable and fixed stations. Customer testimonials and product images illustrate the practical application and build quality of EMTECH's offerings, providing insights into their durability and ease of integration into existing amateur radio setups.

Contruction notes of an Umbrella Loop antenna for AM shortwave listenings

Lots of information of hidding transmitters, building portable yagi antennas, s-meters, and much more

Meter and Low Power Tune for FT-857D

Based on a design by JM1SZY for 50 MHz that he developed using YO

Continuos coverage HF Transceiver by I6WJB & I6YPK

We worry a lot about Standing Wave Ratio (SWR) in amateur radio since SWR is one indication of how well our antenna system is working. Most HF transceivers and antenna tuners have built in SWR meters. SWR is a measure of a transceiver' s output power verses the portion of that power reflected by the antenna system

A 144 MHz kilowatt amplifier project details the construction and performance of a high-power VHF linear using the GU74b tetrode. This Russian tube, equivalent to the Svetlana 4CX800, is noted for its conservative datasheet ratings, performing closer to 800-1000W anode dissipation in practical applications. The design prioritizes compactness and achieves 1.2 kW output with only 20W of drive power, demonstrating a 70% efficiency at 2.5 kV plate voltage. The amplifier has been successfully deployed in demanding _EME_ (Earth-Moon-Earth) operations since June 1994. Challenges encountered during development included achieving stability with a grid-1 input configuration. The author, _CT1DMK_, opted not to publish the full design due to its complexity, suggesting it might be difficult for less experienced builders to replicate successfully. However, he invites direct contact for those with specific interest in the design. Future plans include a "144MHz GS35b compact amplifier" project, promising another kilowatt-plus design. This resource offers insights into high-power VHF amplifier construction and the practical application of specific power tubes.

This site provides free azimuthal maps for almost anywhere on the globe. Create your own azimuthal map for your location. You can customize the map in a variety of ways by changing the options in the web form

Simplified U.S. frequency allocations table by K8ZT

Duplexers for dual band radio are usually high pass filter and low pass filter combined in the same box. This circuit is a design within a cost of US$10.

You'll find more than 330 Amateur Packet Radio Gateways on world maps.

This resource provides a historical listing of **unlicensed amateur radio beacons** active in the United States as of December 1993, specifically detailing both **LOWFER** (Low Frequency Experimental Radio) and **MEDFER** (Medium Frequency Experimental Radio) operations. The data includes beacon frequencies in kilocycles (Kc), identification codes, state locations, and the callsigns or names of the beacon operators. Frequencies range from 166.667 Kc for LOWFER to 1706.0 Kc for MEDFER, illustrating the spectrum utilized by these experimental stations. The information was originally compiled by Mark Burkart and relayed to the rec.radio.shortwave newsgroup by Rick Robinson, KF4AR. The list serves as a snapshot of experimental beacon activity from the early 1990s, offering insight into the types of operations and the individuals involved in unlicensed, low-power transmissions. It highlights specific beacon IDs like "ABC SC" on 510.5 Kc and "GK HI" on 1620 Kc, alongside operator details such as Todd Roberts (WD4NGG) and Herb Vanderbeek (WY6G). While not a current operational guide, it is a valuable historical document for those interested in the evolution of LF/MF experimental radio and the early days of internet-based amateur radio information sharing.

The N2CKH travel special 300 Ohm ladder line convertable antenna

This FET preamplifier has been around for almost 25 years. It is extremely reliable and can handle several watts directly into either the input or the output without failure.

Mars Mod for Yaesu FT-450 extending frequency range: 1.8-30 MHz

The page provides a detailed guide on building a successful 160 Meter short TX loop antenna, with specific dimensions and tuning instructions. It includes information on the design, construction, and tuning of the antenna, as well as the materials required. The intended audience is amateur radio operators looking to build an effective antenna for the 160 Meter band.

remote antenna switching project by EI7BA

Two types of home-brewed 12/20 Ampere 13,8volt power supplies, including detailed part lists by ON6MU

RXCLUS is a free windows amateur radio software especially designed for the DX'ers and SWL's wanting to receive the informations transmitted by packet radio on the DX-cluster system. It supports also telnet protocol.

Maritime frequencies and nets

2m SSB/CW-12.5 Ohm Yagis with extrem high gain and small bandwidth. These Yagis were constructed as ultra-light, portable Yagis with extrem high gain. They have small bandwidth and are working from 144,0-144,8MHz with good SWR.