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FindU.com operates as a robust database archiving **APRS** (Automatic Packet Reporting System) data, including weather, position, telemetry, and message reports. It integrates data from both amateur radio APRS systems and the internet-based Citizen Weather Observer Program. This substantial 58 GB database is hosted on dual servers utilizing data replication, processing approximately 20 new reports per second to provide constantly updated information. The system supports various applications, such as displaying weather reports, tracking position data, and facilitating long-term vehicle tracking. A notable function involves forwarding over 100,000 near-realtime weather observations daily to the National Oceanographic and Atmospheric Administration (NOAA) for accuracy checks and use by NOAA and the National Weather Service. Additionally, it archives APRS reports from the International Space Station. Access to the database is primarily via dynamic web pages, with a comprehensive list of available CGIs detailed on a dedicated server page. While direct URL parameter editing is possible for advanced users, alternative web pages with forms simplify query submission. The platform utilizes **PNG** images for dynamic graphics, a choice made due to past GIF patent issues, ensuring broad browser compatibility.

Build yourself a postage stamp 40 meter wire dipole antenna that fits in a space a little over 20 wide and works reasonably well at low heights

Ham Radio 20 / 40 meter short Coax Trap dipole antenna designed with the coax trap design calculator program

A multiband antenna that can work from 80 to 10 meters in this illustrated docuemnt by G8ODE

Presents a comprehensive guide for constructing a broadband Hex Beam antenna, a popular directional array for HF operation. This design offers a compact footprint and excellent gain characteristics, making it suitable for limited space installations while providing significant performance advantages over omnidirectional antennas. The resource details the specific dimensions for a five-band Hex Beam covering 20, 17, 15, 12, 10, and 6 meters, emphasizing the critical element spacing and wire lengths required for proper resonance and pattern. It outlines the construction of the center post, spreaders, and wire elements, along with the feed point assembly, ensuring proper impedance matching. The project aims for a forward gain of approximately **5.5 dBi** on most bands, with a front-to-back ratio often exceeding _20 dB_. Building this antenna requires careful measurement and assembly, but the resulting performance provides a substantial upgrade for DXing and contesting.

80 meter vertical experiment by Bob Raynor N4JTE

30/17/12 and 20/15/10-Meter Tribanders and a 40 meters inverted V wire yagi antenna

Pictures of a 2 meter, 220, 440 copper J-Pole antennas

This project outlines the construction of a 3-element reversible quad antenna specifically designed for the 40-meter band. The materials required include pushup towers, pressure-treated posts, insulated wire, and various electrical components such as relays and a balun. The construction process is straightforward, beginning with the installation of the posts in a straight line, followed by the assembly of the antenna elements and their elevation to the desired height. The antenna's design allows for directional signal reception, making it ideal for operators looking to enhance their communication capabilities on the 40-meter band. The project includes detailed instructions on tuning the antenna for optimal performance, ensuring that operators can achieve the lowest SWR possible. Additionally, the design can be adapted for other bands by extrapolating dimensions, providing versatility for amateur radio enthusiasts. Overall, this reversible quad antenna project is suitable for both beginners and experienced operators, offering a practical solution for improving signal strength and directionality in 40-meter communications.

A monoband yagi for 14 MHz a PDF article from 73 amateur radio magazine by AB4GX

AB4GX K4EAA Mononband yagi antenna for 20 Meters

YF1AR 80 to 40 meter vertical antenna project

A two elements beam antenna tunable from 6 to 20 meters, based on the Maria Maluca antenna project by DB9EX, in german

A W3DZZ trapped dipole for 80 40 and 20 meters band by ZL1BJQ

Build a spiderbeam from scratch for 20-17-15-12-10 meters band

A wire yagi antenna model, easy to build, made using inverted vee elements and requiring just one support by ve3vn

A three-frequency multi-band dipole that can be extended easily to additional bands. This article includes a multiband fan-dipole antenna for 80-40-20-10 meter band.

This is a popular antenna design as the performance is very good across the HF bands and requires little or no tuning. It is a dipole fed off center with a 4:1 current balun at the offset feedpoint. The antenna shown covers 80, 40, 20 and 10 meters with 15 meters and WARC bands

The ZS6BKW wire antenna, a variant of the G5RV, utilizes a specific 13m (42.6 ft) length of 450-ohm window line as its matching section, feeding a 28.5m (93.5 ft) flat-top element. This design aims for lower SWR on 40m, 20m, 17m, 12m, and 10m compared to a standard G5RV, often achieving SWR values below 1.5:1 on these bands without an antenna tuner. The feedpoint impedance transformation provided by the window line allows for direct connection to 50-ohm coax on multiple bands. F4FHH's experience involved constructing the ZS6BKW and evaluating its performance against an _OCF dipole_ (Off-Center Fed) on various HF frequencies. The article includes observations on SWR readings and operational effectiveness, highlighting the ZS6BKW's suitability for multi-band operation. The antenna's overall length, including the flat-top and window line, is approximately **41.5 meters** (136 feet), making it a significant wire antenna for fixed station use. Comparative analysis with the OCF dipole provided practical insights into the ZS6BKW's advantages and limitations, particularly concerning bandwidth and tuner requirements.

An home made trapped dipole antenna for 40 and 60 meters band by 2E0HTS

Presents the detailed construction of the _FLA25HV_ antenna, a specialized array optimized for Earth-Moon-Earth (EME) communications on the 2-meter band. This resource provides schematics and practical insights into building a high-gain antenna system capable of reflecting signals off the lunar surface, a challenging but rewarding aspect of amateur radio. It covers the mechanical and electrical considerations essential for achieving the precise pointing and signal strength required for successful moonbounce contacts, often yielding **20 dB** or more gain. Amateur radio operators pursuing EME operations require robust antenna systems and precise tracking capabilities. The FLA25HV design addresses these needs by focusing on element spacing, impedance matching, and structural integrity to withstand environmental factors while maintaining critical alignment for lunar reflections. Such systems are crucial for making contacts over distances exceeding **768,000 km**. This personal page serves as a practical guide for hams interested in constructing their own EME arrays, offering a glimpse into the technical dedication involved in pushing the boundaries of VHF/UHF propagation.

Moxons work great, and they take up less space than full size two element Yagis

Pictures of a 2 element cubex Quad antenna at a height of 10 meter

A popular 2 meter antenna returns in an improved, easier to reproduce form, 2008 QST article

A telescopic pole that you adjust to suit the band you're working on , tested on 40 20 and 15 meters band by M0PZT

An 87ft inverted L portable antenna working on 80 40 30 20 15 meters band

A beam fractal antenna for 20 meters band

A basic drawing of a 2 meter quad antenna for 144 MHz

VQLog 3.1 - 782 is a shareware logbook program designed for Windows operating systems (95, 98, NT, 2000, ME, XP, Vista, 7, 10, or later), supporting resolutions of 800x600 or higher. It can also operate on macOS and Linux via virtualization software like Virtual PC for MAC, Oracle VirtualBox, or VMware. The software facilitates QSO access by date, callsign, prefix, square, DXCC, and other parameters, offering robust import capabilities for ADIF, Cabrillo, and ASCII files from various contest and logbook programs. Key features include comprehensive award tracking for DXCC, WAZ, WAC, WPX, WAS, IOTA, TPEA, DIE, VUCC, 100EACW, and up to 30 user-defined awards. It generates customizable summaries and graphical statistics for QSO activity, DX contests, Most Wanted Squares (MWS), propagation openings, and prefixes. VQLog supports DX-Spot reception and processing from DX-Cluster and PSK-Reporter with programmable warnings, integrates with callbook services like QRZ.COM and Buckmaster's CD, and offers online lookup. Electronic QSL and log upload support extends to LoTW, eQSL.cc, Clublog, and DXMAPS, with real-time updates for online logs. The program provides extended QSO information for VHF-DXers, including separate TX/RX frequencies, start/end times, propagation modes, and specific entry fields for MS, EME, and Tropo. CAT support for rig control and interfaces with ARSWIN and PstRotator for azimuth/elevation control are also included.

A half-sized Hentenna designed for unique performance in compact spaces. Initially built in 2003 for monitoring a local 146.97 MHz repeater from a basement shop, the antenna proved highly effective, operating at just 200mW. In 2005, it was adapted for use in a challenging river-bottom location, delivering reliable performance on a 2-meter band with 5W. Despite its compact size, the Forktenna demonstrated excellent results compared to a full-sized Hentenna, making it an intriguing option for many hams.

The RTTY Net is one of several Nets run by the 3905 Century Club. There are SSB Nets on 160, 75, and 40 Meters and CW Nets on 80 and 40 Meters

This array has been in use since 1989. The SWR from 3.5 to 3.9 is below 1.5:1. The F/R of the array is 20dB average and with some signals even better.

Operating a ZS6BKW antenna often involves understanding its lineage from the _G5RV_ design, with specific modifications by ZS6BKW to optimize performance on several bands. Through computational analysis and field measurements, the antenna's dimensions were refined to allow operation on 10, 12, 17, 20, and 40 meters without an antenna tuner. For 80, 30, and 15 meters, a tuner is necessary, though efficiency on 30 and 15 meters is noted as not particularly high. The physical configuration consists of two 13.755-meter radiating elements fed by a 12.20-meter section of 450-ohm ladder line. Tuning the antenna on the 20-meter band is critical, and any deviation in the ladder line's characteristic impedance necessitates recalculating the element lengths. The design is also referenced in the 12th edition of _Rothammel's Antennenbuch_, page 219. Proper common mode current suppression is crucial at the transition from ladder line to coaxial cable. This can be achieved with a common mode choke, such as several turns of coax wound into a coil or over a ferrite toroid like an Amidon T130. While a 1:1 balun is an option, it may introduce issues.

40 meter vertical antenna construction, a shortened easy-to-build vertical, with no-radials, made from surplus military camouflage poles

A vertical dipole for 10, 15, 20 and 40 meters made adapting two Hustler Model 6-BTV antennas by w6sdo

A three element wire yagi antenna for 7 MHz project plan with drawings and EZNEC model

G3WZT John Matthews project of a 600 Watt solid state linear amplifier for the 6 meters band

Demonstrates the design and construction of a 9-element Yagi antenna for the **70 cm band** (432 MHz), based on the DK7ZB concept. The resource details EZNEC+ calculations for a single antenna, providing gain, sidelobe suppression, and front-to-back ratio figures. It also presents a comprehensive analysis of stacking two such antennas, including optimal stacking distance (1000 mm) and the resulting performance enhancements for the stacked array, such as an increased gain of 17.03 dBi. The article includes detailed drawings, wire file dimensions in millimeters, and azimuth/elevation plots for both single and stacked configurations. Practical construction steps are documented with original photographs, illustrating element mounting, the **28 Ohm matching system** using two quarter-wave 75 Ohm transmission lines, and the critical N-connector wiring. It also covers the iterative process of fine-tuning the driven element length to achieve a return loss of 20 dB, validating the EZNEC+ simulation results with actual measurements.

An 85ft wire fed against a 17ft counterpoise that works well in 80 and 40 meters

This project was published in the April 2004 issue of the Australian magazine Amateur Radio, and has been designed using parts which are very readily available.

A multiband dipole antenna that can work on 15 20 and 40 meters band made with common materials

A project for a homemade multiband Hexbeam antenna for 10, 12, 15, 17 and 20 meters

Conversion of Zetagi HP201 SWR wattmeter for HF Amateur Bands by G8ODE

A five element quad antenna for 144 MHz DIY Project. This 2 Meter 5 Element Quad antenna was modeled using EZNEC, with a boom from a UHF TV antenna and CPVC pipe for spreaders. Constructed for 146MHz, it exhibits a gain of 10.7dB and an impedance of 75 ohms. Real-world results surpass the HT antenna, reaching over 20 repeaters up to 75 miles away. The design, costing around $10, employs simple tools for assembly.

A simple 7 bands off-center dipole wire antenna designed to work on 80 meters band and that can cover also 40m 30m 20m 15m 12m 10m with acceptable SWR

This HALO design is not ground dependent and can be mounted atop a section of PVC.

Presents a construction project for a linear-loaded 40-meter rotatable dipole, detailing the design evolution from mid-element coils to 300-ohm twinlead loading. It covers material selection, including repurposed fishing poles and EMT conduit, and outlines the assembly process for the antenna elements and mounting plate. The resource provides specific measurements for element lengths and linear loading sections, along with SWR plots demonstrating the antenna's resonance at 7.035 MHz with a 1.1:1 SWR, and bandwidth up to 7.120 MHz below 2:1 SWR. The article documents the antenna's performance during various RTTY and CW contests, including the SARTG RTTY and SCC RTTY contests in August 2006, and the ARRL DX CW and CQWW WPX RTTY contests in February 2007. It reports successful operation at 500-1000W, noting improved performance after replacing a faulty coax cable. Specific DX contacts from British Columbia, including stations in Europe and South Africa, are listed, illustrating the antenna's capability despite its shortened length and relatively low height of 55 feet. The content highlights practical considerations such as weatherproofing the connections and supporting the fiberglass elements to prevent sagging. It also includes a brief comparison to an inverted-V at similar height and a ground-mounted vertical, noting the rotatable dipole's quieter reception. The author shares insights into the iterative design process and tuning adjustments made to achieve optimal resonance.

A 10 meters band Slim Jim antenna project, made with a 450 Ohm slotted ribbon cable and secured on a 8 m fishing pole, by Steve G0KYA

Tuning the Solarcon Antron A-99 antenna for 20 meters band

A vertical portable antenna system by W0SJS that will work on 40, 30, 20, 17 and 15 meters