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Details the construction of a **multiband vertical** antenna, specifically designed for stealth operation in a rented property, covering 80m, 60m, 40m, and 30m. The author, N3OX, leverages a 12m Spiderbeam telescoping fiberglass pole as the primary support, noting its sturdiness compared to typical fishing rods while remaining light enough for quick deployment and takedown. The radiating element is a 14 gauge Flex-Weave wire, attached to the pole's top with a rubber grommet, and fed by 27 bare 18 gauge radials spread across a 40-foot square backyard. N3OX describes the impedance matching solution, opting for custom-built L-networks over a remote tuner to enable fast bandswitching. Using an MFJ-259B and EZNEC modeling, base impedances were measured and component values calculated with G4FGQ's L_TUNER and SOLNOID_3 programs. The 80m coil is wound on a 3.5-inch PVC form, while the 30m, 40m, and 60m coils are air-wound, self-supporting #10 wire. Variable capacitors are incorporated for 40m and 30m shunt elements, with the 60m impedance matched by a series inductor. The project includes a **servo-controlled** homebrew band switch, utilizing a two-pole 12-position ceramic wafer switch for remote operation, addressing the limited 80m bandwidth. The entire matching network is housed in a weather-resistant shelter constructed from lumber and aluminum flashing. N3OX reports good DX results at 100W, estimating the total cost between $150 and $250, depending on existing parts.

How to make the Super antenna. To build this antenna you need a lot that is at least 100 feet across. Antenna covers all bands 80-10 meters + 30, 17, 12 meter WARC Bands This antenna works as a Full Wave Loop on 80 Meters and also works as a 2 wavelength open loop or Bi-Square on the 40 Meter band

The HB9ABX mobile HF antenna, developed by _Felix Meyer_, offers a high-performance alternative to commercial mobile antennas for 80 through 10 meters. Constructed from fiberglass rods and enamelled copper wire, this design incorporates a loading coil with multiple taps, allowing for band-specific tuning. The article provides detailed instructions for winding the coil, connecting the antenna elements, and integrating it with a vehicle's chassis ground. Field tests conducted at 100W consistently showed the HB9ABX antenna outperforming a HUSTLER mobile antenna by up to **10 dB** (1 S-point) and a YAESU ATAS-100/120 by **18 dB** (2-4 S-points) across distances from 5 km to 1000 km. The design emphasizes a robust ground connection and the use of an antenna tuner, such as an _MFJ-901B_, for optimal SWR on all bands, particularly 40 and 80 meters. Initial adjustment involves setting whip length and coil tap positions to achieve resonance without a tuner, followed by fine-tuning with the tuner during operation. Specific measurements are provided for checking resonance on 21.0 MHz and 14.2 MHz, with precise turn counts for the lower (79 turns) and upper (120 turns) antenna sections. Safety precautions for handling fiberglass dust are also highlighted.

For amateur radio operators utilizing _APRS_ or requiring an external antenna for their GPS receiver, this resource details the construction of a compact, circularly polarized mobile antenna. The design is based on a classic turnstile configuration, employing two dipoles rotated 90° from each other and spaced a quarter-wavelength above a ground plane. A parallel-plate transmission line, fabricated from printed circuit board material, serves as both the connection method and mounting post for the dipoles, simplifying the feed network for circular polarization at 1.57542 GHz. The article outlines the fabrication process, starting with a 4-inch diameter hobby tin or brass base plate and #14 solid copper wire elements. It specifies using _RG-58/U_ or similar 50-ohm coax, with an 8-foot maximum length to minimize loss at the GPS frequency. The parallel-plate transmission line is constructed from two 2-inch lengths of single-sided _FR-4_ or G10 PCB material, 0.062-inch thick, with a specific 45° microwave turn cut on the active side. Final assembly involves an 8-ounce cream cheese container as a radome, and the article discusses the self-phased quadrature feed method to achieve circular polarization without a coaxial phasing line, resulting in an omnidirectional pattern suitable for GPS satellite reception.

Presents the KE4UYP linear-loaded vertical antenna design, which introduces very little loss on 80 or 160 meters, achieving an overall radiation efficiency of 80% to 85%. This design addresses common pitfalls of traditional base-fed verticals by placing the majority of the current at the top of the antenna, eliminating the heavy reliance on extensive ground radial systems. The author's initial 10-meter model, only three feet tall, yielded 5/9 signal reports to Anchorage, AK, and Europe, confirming its effectiveness. The antenna incorporates both vertically and horizontally polarized radiators, with a 1/4 wavelength horizontal counterpoise located at the feed-point, near the top, to create an almost totally omnidirectional pattern with high wave angle horizontally polarized radiation. This dual polarization ensures even illumination across all take-off angles, making it effective for both local contacts and **DXing**. The vertical element is linear loaded, adding capacitance reactance and making it longer than the horizontal element to achieve resonance and raise the feed-point impedance to 50 ohms. Fine-tuning the antenna requires careful adjustment, as tower reactance can vary. The article suggests starting with 80 feet for 80m and 170 feet for 160m for the vertical wire, then trimming for resonance. Bandwidth specifications include 300 kHz under 2:1 **SWR** on 80m and 100 kHz on 160m when suspended between trees, or 150 kHz on 80m when side-mounted on a tower.

M1PAF's 20 Meter Vertical Moxon antenna design, based on Pete Mills' EZNEC model, utilizes a push-up GRP mast and Tufnol plate for mounting cross arms, minimizing metallic elements within the beam. Hydraulic pipe clamps, also plastic, secure the tube clamps, with only two bolts and a plate being metallic. Dog bone insulators with Kevlar line and snap links facilitate quick wire element attachment, ensuring tension in all dimensions. The antenna's support structure includes Tufnol guying rings for Kevlar guys, providing stability against high winds. The cross arms are constructed from three 1-meter sections, allowing for convenient packing. This portable setup was successfully deployed adjacent to the ocean, enabling over 4500 QSOs in six days with 100W, achieving easy contacts into Japan and Asia. The design emphasizes ease of erection by a single operator and robust performance in challenging environments. Components for the cross arms were sourced from Spiderbeam. Further information is available via M1PAF's QRZ.com details.

SM0DTK's 40-meter Moxon antenna project details the construction and deployment of a wire Moxon rectangle, specifically dimensioned for the 7 MHz band. The resource outlines the use of a _Moxon Rectangle Generator_ for calculating wire lengths and the fabrication of plexiglass supports for corners and the feeding point. It describes the practical challenges of elevating the antenna to approximately **14 meters** using an aluminum tube and fiberglass rod, emphasizing the adjustment process for achieving the correct rectangular shape. The article presents comparative results against a 60-meter long-wire and a full-size 40-meter ground plane antenna. The Moxon demonstrated significant directional gain towards the west, facilitating DX contacts in the Caribbean with **100 watts**, while simultaneously reducing QRM from strong eastern European stations. The SWR was reported as perfect without the need for an antenna tuner, validating the design's effectiveness for targeted signal enhancement and interference mitigation.

Selecting an appropriate antenna system for shortwave broadcasting involves evaluating various types based on performance, cost, and operational parameters. This resource details the critical specifications for broadcast antennas, including average and peak power ratings, directivity, takeoff angle (TOA), horizontal beamwidth, and gain, emphasizing that a 100-kW transmitter requires an antenna rated for 150 kW average and 400 kW peak. It clarifies that low TOA signals travel thousands of kilometers, while high TOA is for local coverage, and nearly all modern shortwave broadcast antennas are horizontally polarized. The article explores specific antenna types, such as Log-Periodic Antennas (LPAs), which offer wide frequency ranges (e.g., 2-30 MHz) and directional patterns with 11 dBi gain, costing from $20K to over $100K for multi-curtain versions. Dipole arrays, also known as curtain antennas, are prevalent in international broadcasting, featuring steerable beams (±15° and ±30°) and mode-switching capabilities to alter TOA, with high/low pairs costing over $1 million. Fan dipoles are noted for omnidirectional patterns, smaller size, and lower cost for low-power applications, while rhombics, though simple, require resistive termination and incur several dB of I2R losses. Balun considerations are crucial, as most communications baluns are not rated for the higher average and peak powers of AM broadcast transmitters. Modern shortwave antennas utilize durable materials like Alumoweld wire rope for radiators and support elements, avoiding copper, fiberglass, or materials prone to stretching or deterioration. Feeder systems for high-power stations often require tapered-line baluns to convert 50-ohm unbalanced power to 300-ohm balanced for connection to the antenna.

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.

W5ALT Indoor Vertical Antenna is a base loaded vertical antenna that can be tuned on almost all HF bands by adjusting a big coil. Operating a ham radio station from an apartment in Maracaibo, Venezuela, the author demonstrates effective communication with over 100 countries using a custom-built indoor vertical antenna. Addressing common misconceptions, the design uses a balanced approach with radials and a base-loaded vertical element made from affordable materials. The antenna fits discreetly indoors, covers 6 to 40 meter bands, and achieves acceptable SWR with an MFJ tuner. Despite limited space and typical apartment challenges, the setup enables reliable DX contacts, confirmed by numerous QSL cards, proving indoor antennas can perform well in constrained environments.

The "Largest YU Moxon" document details the design and construction of a substantial multiband Moxon antenna, primarily for 80m, 40m, and 20m operation. It presents specific design parameters derived from NEC-based simulations, including a 4-element 80m Moxon with 37 dB F/B and 7.81 dBi gain on a 47m boom, a 4-element 40m Moxon with a bidirectional pattern, and a 6-element 20m Moxon optimized for specific side lobes. The resource provides precise element lengths and spacing in meters for each band, alongside measured SWR results across the 3.650-3.800 MHz, 7.000-7.100 MHz, and 14.000-14.350 MHz segments. The construction narrative outlines the challenges and solutions encountered by the YU team, including the use of trees for support, the creation of "ugly" air-choke baluns from RG-58 cable wound on plastic bottles for each band, and the meticulous process of attaching wires to a rope boom. It documents the physical dimensions of the vineyard site (47 x 38m) and the azimuth orientation (340 degrees) chosen for the antenna. The document is distinctively useful for its practical insights into large-scale antenna deployment in a field environment, offering real-world SWR measurements and anecdotal performance reports from CQWW contest operations. It includes numerous photographs illustrating the construction process, the team members, and the finished antenna structure, providing visual context to the technical details.

Autotena, a Taiwanese manufacturer, offers a diverse product line focused on RF communication antennas and related accessories. The resource details various antenna types, including **4G/3G LTE wideband high-gain low-profile antennas**, land mobile wideband antennas, fiberglass omnidirectional designs, and GPS mobile and marine antennas. Specific amateur radio offerings include NMO VHF load coil gain antennas, VHF whip gain antennas with PL-259 connectors, and UHF NMO mount antennas with 3dB/5dB gain. The company also produces antennas for CB and 10-meter amateur bands, such as aluminum broadband 26-30MHz antennas and big copper coil broadband 26-30MHz antennas. Additionally, the site showcases **RF amplifiers** for CB, HF, VHF, and UHF bands, including professional-grade base station amplifiers with 100% EIA duty cycle. Handheld antennas, PL-259 type mobile antennas, magnet mount antennas, and external CB speakers are also presented, alongside various mounting kits and cable assemblies.

End-Fed Half-Wave Antennas (EFHWAs) are analyzed for their utility in portable QRP operations, emphasizing their simplicity, efficiency, and predictable radiation patterns compared to other portable antenna types. The discussion contrasts EFHWAs with vertical antennas, random length wires, and center-fed dipoles, highlighting the common pitfalls of each, such as ground system dependency for verticals and feedline issues for dipoles. The article details the electrical half-wavelength calculation using the formula L (Ft) = 468/F(MHz) and explains how EFHWAs can be resonant on harmonic frequencies, enabling multiband operation. Various deployment configurations are presented, including the inverted L, inverted Vee, sloping wire, and vertical setups, each with specific advantages for radiation angle and polarization. For instance, a vertical EFHWA offers a low angle of radiation suitable for DX contacts without requiring an extensive ground system. The resource also addresses the counterpoise requirements, suggesting a quarter-wavelength wire or connection to a metallic structure for decoupling. A schematic diagram for a simple parallel-tuned circuit tuner, based on the _Rainbow Bridge/Tuner_ design, is provided, detailing component values for 30 and 40 meters, including a 6 microhenry toroidal inductor and a 20-100 picofarad mica compression capacitor. The tuner's adjustment process for SWR matching is also outlined.

Details a practical QRP wattmeter construction, leveraging a simplified SWR meter design by JA6HIC. The project focuses on a forward-only power measurement circuit, providing a functional instrument for RF power levels from milliwatts up to 5 watts. It maintains a 50-ohm input and output impedance, suitable for typical QRP transceivers and antenna systems. The resource includes the schematic for the "VSW" (Very Simple Wattmeter) and outlines a six-step alignment procedure. This calibration process involves using a known RF source up to 5W, setting full-scale deflection, and marking power increments. It also addresses minimizing frequency effects on readings with a 100pF trimmer capacitor, noting that measurement error is highest at the lower end of the scale. Construction notes mention using a piece of RG-213 coaxial cable for the inductance and coupler, with the wattmeter assembled in early 2003. The author provides an example measurement showing 0.8W into a dummy load and 1W into a 3-element beam.

This PDF document, authored by KT4QW in October 2004, details the construction and modeling of a dual-band, horizontally polarized hanging rectangular loop antenna for **10 and 17 meters**. The design, adapted from *The ARRL Handbook*, utilizes _NEC4WIN95_ software for scaling and optimization, targeting a 50 ohm feedpoint impedance. The resource includes a bill of materials, step-by-step construction instructions, and a discussion of the antenna's radiation characteristics. It presents NEC-generated elevation and azimuth patterns, comparing the loop's performance to a half-wave horizontal dipole at the same height and frequency. The 17-meter element is centered at 18.140 MHz for low SWR across the phone band, while the 10-meter element is centered at 28.500 MHz. Construction involves 14-gauge stranded copper wire and Schedule 40 PVC spreaders, with the total wire length calculated by the formula: Length in feet = 1005/MHz. The feedpoint impedance can be adjusted by modifying the rectangular aspect ratio. The document specifies hoisting the antenna to at least a half-wave above ground for testing. It notes that a balun was tested and found to have no measurable effect on SWR or radiation characteristics. A 2-meter scale model is presented to illustrate the physical design, and a "rotator" string is incorporated for directional adjustment up to 90 degrees.

This article documents an unobtrusive antenna for operation on 7MHz, primarily for contacts with stations at up to 1000Km range.

The perfect tool when you want to put up a wire antenna easily, quickly and safely! EZ HANG can be used to "shoot" a line over a tree or other object over 100 feet high

This project is intended to aid in tuning a balanced antenna or feedline that has a high impedance 100-600 ohms

The article "Exploring the World of 10 Meter Beacons" by Ken Reitz, KS4ZR, provides an in-depth look at 10-meter beacon operations, focusing on their utility for propagation analysis. It details FCC Rules part 97.203 governing beacon stations, including license requirements, power limits (under 100 watts), and the specified band segment of 28.200-28.300 MHz for U.S. operations. The content highlights the diversity in beacon construction, from converted CB radios to home-brew QRP transmitters, and discusses the robust operating conditions these 24/7 stations endure. The resource presents several case studies of active 10-meter beacon operators like Ron Anderson KA0PSE/B, Domenic Bianco KC9GNK/B, and Bill Hays WJ5O/B, detailing their equipment, antenna setups, and typical signal report volumes. It also introduces the NCDXF/IARU International Beacon Project, which features 18 synchronized beacons worldwide transmitting on 28.200 MHz at varying power levels (100W, 10W, 1W, 100mW) to facilitate propagation testing. The article also covers the PropNet Project utilizing PSK31 on 28.131 MHz and the 250 Synchronized Propagation Beacon Project on 28.250 MHz. Practical advice for monitoring includes using the RST reporting method, understanding the impact of the solar cycle on 10-meter propagation, and tips for setting up a personal beacon, such as frequency selection and power output considerations. The IY4M Guglielmo Marconi Memorial Beacon Robot on 28.195 MHz is also mentioned for its automatic QSO mode. The article concludes with a list of other resources for 10-meter beacon information.

Determine the K-Factor used as a multiplier when constructing half-wave antennas.

Constructing a compact, two-band magnetic loop antenna for HF operation, especially from constrained locations like a balcony, presents unique challenges. OK1FOU's design, inspired by DJ3RW's 50 MHz loop, addresses these by employing an unusual side-fed configuration and placing the symmetric, two-section variable tuning capacitor at the bottom of the loop, directly connected to the coax shield. The article provides specific material recommendations, including two 1-meter wooden pales and about 3 meters of thick loudspeaker cable, noting the high current (60A at 100W) in the loop. Construction steps detail forming two turns with a 5 cm gap, using a GDO to pre-tune the open loop to a frequency slightly above the desired highest band, and then integrating the tuning and coupling capacitors. For 10/14 MHz, an open loop resonance of 16-17 MHz is suggested. Practical experience with the 10 MHz band from a third-floor balcony in Prague (JO70GC) shows a 1:1 SWR across most of the band without an external ATU. While DX traffic was modest due to the urban environment, QSO examples with RA6WF, LA6GIA, G0NXA, and LZ1QK on 10 MHz are provided, demonstrating its operational capability.

JJ0DRC's HF multi-band delta loop antenna project, initially conceived during the waning peak of Cycle 23, addresses the common challenge of achieving effective DX operation from a small residential lot in Japan. Dissatisfied with a ground plane antenna's performance in SSB pile-ups, the author sought a beam-like solution without a tower, drawing inspiration from a JJ1VKL article in CQ Ham Radio Sep. 2000. The antenna, constructed in October 2000, employs two 7.2-meter fishing rods (37% carbon fiber, reinforced with cyano-acrylate glue and aluminum tape) and 1mm enameled wire, fed by an Icom AH-4 external antenna tuner. While the exact beam pattern remains unmeasured, JJ0DRC observed a significantly higher callback rate compared to dipole antennas, particularly on higher bands. The system's circumference length of 15-20m is crucial for maintaining a good beam pattern across HF bands, though performance on lower bands like 80m, 40m, and 30m becomes less directional as the length deviates from a full wavelength. Ongoing maintenance addressed degradation issues, including aluminum tape cracking and wire breakage at connection points due to strong winds (often exceeding 10-15m/s in winter). The author reinforced rod connections with IRECTOR PIPE SYSTEM components and INSU-ROCK ties, and improved wire attachment methods using Cremona rope and epoxy bond to enhance durability.

This is an attempt to build an Antenna rotator controller using Arduino Mega 2560 with a nice user interface showing the actual position of the antenna.

The W1TAG LF Receiving Loop is a specialized antenna project for LF reception, designed to mitigate local noise and enhance weak signal pickup on the lower frequencies. This square loop, measuring 6 feet per side, utilizes 14 turns of #12 THHN wire wound on a PVC frame, offering a robust mechanical structure. The design incorporates a series-tuned circuit with a coupling transformer, allowing for tuning from over 400 kHz down to _45 kHz_ using a switched capacitor bank. Construction details include the use of 1.5-inch PVC pipe for the frame, with specific measurements for spreaders and drilled holes for wire threading. The two 7-turn sections of wire are connected at the center, providing an option for a center tap. The loop rotates on a 1-inch steel pipe, enabling directional nulling of noise sources. The tuning unit, housed in a box clamped to the PVC, employs a 1:2 step-up transformer wound on an _FT-82-77 core_ and uses relays to switch capacitance values from 50 pF to 6400 pF, providing precise frequency adjustment. The current setup connects to the shack via 100 feet of RG-58, feeding into a W1VD-designed preamp, with plans for a balanced, shielded twisted pair cable upgrade.

A portable VHF home-made Yagi-Uda antenna, that is extremely easy to build and very cheap. Moreover this antenna, while dismounted is just 1 meter long, and the total weight is just 100 grams.

The Q-signal **QRP** signifies a request to reduce power, and in amateur radio, it defines operating with 5 watts or less for CW and 10 watts or less for SSB. This article addresses common inquiries from new hams regarding the practice, its benefits, and implementation methods. It explains how a 5-watt QRP signal, compared to a 100-watt signal, typically results in only a 13dB drop in signal strength, equating to about two S-units, still providing solid copy under most conditions. Hams choose QRP for various reasons, including seeking a greater challenge in DXing or contesting, reducing band interference, or enabling portable field operations with lightweight, battery-efficient equipment. A modern single-band CW transceiver, key, and antenna can fit into a pocket, offering receiver performance comparable to commercial rigs and extended operation on a small battery. This portability facilitates operations in remote locations where higher-power setups are impractical. Operating QRP can involve simply reducing power on an existing commercial HF rig or building a dedicated QRP transceiver from a kit, such as the **Wilderness Radio SST** with its 2-watt output and 15mA receive current draw. While SSB is viable, CW remains the most popular and efficient mode for QRP due to its superior signal-to-noise ratio. The article lists common QRP calling frequencies across 160m through 10m bands for both CW and SSB, and highlights organizations like QRP ARCI and NorCal that support the QRP community.

The K0RWU 75-meter mobile antenna design features a 7.5-foot overall length, incorporating a 2.5-foot loading coil wound with #20 enamel wire on a 1/2-inch fiberglass rod, subsequently covered with 1/2-inch shrink tubing to increase diameter to 3/4 inch. This configuration achieved resonance at 3965 kHz with a 5-foot stainless steel whip. The antenna integrates a matching transformer, identified by larger turns near the PL259 connector, and is constructed using a modified Radio Shack CB antenna base. Construction involves drilling and epoxying a 1/2-inch fiberglass rod into a PL259 connector, feeding #20 enamel wire through the rod, and winding 17 turns of #18 matching coil wire between the PL259 sleeve and the center feed point. The main loading coil fills the 2.5-foot rod section. The design allows the antenna to bend for garage clearance and emphasizes maintaining a 50-ohm feed impedance to prevent vehicle electrical damage. The author also discusses experiences with a Yaesu ATAS-100 motorized antenna and a 10-meter antenna project, noting issues with auto couplers and the ATAS-100's performance on 17 meters. Future modifications considered include adding a small servo for band spreading and increasing the fiberglass rod length for a 3-foot loading coil to improve bandwidth. The antenna's sharp tuning, between 3960 kHz and 3970 kHz, necessitates careful adjustment of coil turns for optimal VSWR.

Demonstrates the iterative design and construction of a **tapped HF/VHF mobile vertical antenna** by K0EMT, detailing four generations of development. The antenna supports operation on 80m, 40m, 30m, 20m, 17m, 15m, 12m, 10m, 6m, and 2m bands. Initial designs, like Generation 1, featured a 3/8" x 24TPI bolt in a PVC end cap with a 1" aluminum tubing mast, resulting in a 9'9" overall length and resonance around 6.9 MHz with the full coil. Subsequent generations refined the mast and coil forms, transitioning from aluminum to copper tubing (Generation 3, found too weak) and eventually fiberglass for the coil form (Generation 4, in progress). Coil tapping points were adjusted to achieve resonance without an external tuner in Generation 2. The project outlines material costs, totaling approximately $25, and mentions a successful 28 MHz QSO with EA3XA using an ICOM IC-706 mk II at 100 Watts. For 80m operation, an external wire with the maximum coil setting is used, or a 56" extender below the coil for stationary use.

Details the construction of a **17-meter Moxon Rectangle** antenna, specifically engineered for mounting on a mast beneath an existing beam. The design incorporates insulated wire calculations (0.95804 x generator length) to compensate for velocity factor differences, utilizing readily available materials such as crappie poles for elements, PVC for the boom and mast, and a Budwig HQ-1 dipole connector for the 50 Ohm coax feed. The project outlines a step-by-step assembly process, including mast construction from PVC T-connectors and pipe, element fabrication from crappie poles, and securing elements to prevent droop. Initial testing demonstrated an SWR of 1.3:1 on 17 meters, achieving a 5-8 signal report into Texas with 100 watts. Subsequent reinforcement and elevation of the antenna resulted in a 15 over 9 report from Florida. Comparative testing against an 88-foot center-fed Zepp antenna indicated superior performance, with the Moxon consistently outperforming the Zepp and receiving signals the Zepp could not. A notable DX contact with JA8NFV in Hokkaido, Japan, yielded a 5-9+ signal report both ways using 100 watts.

A different approach can help you optimize attic-bound aerial by W6HPH

Demonstrates the construction of two distinct wideband RF preamplifiers, detailing their component requirements and performance characteristics. The first design leverages monolithic microwave integrated circuits (MMICs) such as the MAR-6, MAR-8, or PGA103, offering a broad frequency response from DC to 2 GHz with a gain of 22.5 dB at 100 MHz and a noise figure typically below 3 dB. This MMIC-based amplifier incorporates protection against power supply transients and features a 50 Ohm input/output impedance, operating from an 8-20 volt supply with low current drain. The second preamplifier design utilizes a BSX-20 transistor, providing amplification across the 14 MHz to 550 MHz range. This simpler, more economical build achieves an average gain of 12 dB at 145 MHz and a noise figure of approximately 1.1 dB. It operates from a 7-15 volt battery supply with a current draw of 6 mA. Both projects emphasize critical construction techniques, such as maintaining short RF connections, ensuring 50 Ohm impedance paths, and mounting the circuit within a shielded enclosure to optimize performance and minimize noise. The resource also discusses phantom power options for antenna-mounted preamplifiers and precautions for use with transceivers, including output protection diodes and static bleeders.

A 90-foot vertical antenna constructed from **aluminum irrigation tubing** is detailed, focusing on its innovative raising and lowering mechanism. The resource describes a **45-foot ginpole** system, allowing a single operator to erect or lower the antenna in minutes. It covers the mechanical design, including the pivot base, insulated joints for the tubing sections, and guy wire attachment points. The antenna consists of two 30-foot sections of 4-inch tubing and one 30-foot section of 2-inch tubing, stacked with the smaller diameter at the top. The electrical design incorporates PVC "condulet" boxes at the 30-foot and 60-foot points, housing relays to change the effective height for multi-band operation on 160, 80, 40, and 30 meters. Ferrite rod inductive chokes are used for DC control and to tune out gap capacitance. The antenna is fed with 1000 feet of open wire line, connected to a matching transformer comprising stacked toroids and a coaxial/toroidal balun. Grounding is achieved with a 3x3 foot grid of 16-gauge tinned copper wires with soldered crossovers.

Presents a detailed construction guide for a **Quadrifilar Helix Antenna** (QHA) optimized for 137 MHz, specifically for receiving weather satellite transmissions. The resource outlines the author's experience building previous QHA designs, highlighting challenges with tuning and nulls, and then focuses on a refined design by John Boyer, documented by Steve Blackmore, which proved easier to build and yielded superior reception. The guide provides precise element dimensions, including 1.5m of 32mm PVC pipe for the mast and 8mm soft copper tubing for the helix elements. It specifies lengths for horizontal tubes (190mm, 90mm) and helix elements (903mm, 1002mm), along with instructions for drilling, assembly, and forming a **balun** by wrapping RG58 coax around the mast. The text emphasizes critical steps like ensuring elements are square and twisting in the correct direction to avoid phase issues. It includes references to original QST articles by Buck Ruperto (W3KH) and the WxSat program for decoding satellite transmissions, contextualizing the antenna's purpose. The article concludes with a sample NOAA 12 image from September 1998, demonstrating the antenna's reception capabilities.

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.

Simple, easy to build, low cost, compact, multiband By Robert Wilson, AL7KK

This project produces an inexpensive, multiband, end fed HF antenna matchbox, quick and easy to setup. This project creates a trifilar wound, 9:1 UNUN toroid matching transformer. Handles 100W and need an antenna tuner.

This low power transmitter is developed for ARDF exercising purposes but of course can be used as super QRP transmitter either. With 1 or 2 meter wire as antenna and a ARDF receiver with ferrite-rod antenna the range is about 100m but with better antennas and a 'real' receiver the range is probably much larger.

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.

The SARK100 Antenna Analyzer it is yet another antenna analyzer but available in kit form and designed to be easy to assemble and with an affordable pricing.

With over 20 years of experience, Proyecto 4 operates as a specialized ham radio retailer in Madrid, Spain, providing a diverse inventory of transceivers, antennas, and related accessories. The store features popular models like the _ICOM IC-705_ and _ICOM IC-7300MK2_, alongside Yaesu transceivers such as the _FTX-1 Optima_, which delivers 100W on HF and 50W on V/UHF bands. The product range includes mobile and portable antennas, such as the D-Original DX-NR770HB, offering 3 dB gain on 144 MHz and 5.5 dB on 430 MHz, and the Diamond RH-770 with a BNC connector. CB radio enthusiasts can find the Anytone CB SMART II AM/FM transceptor and the Telecom LS145 mobile antenna, rated for 500W and 4 dB gain on 26-30 MHz. Proyecto 4 emphasizes its in-house technical service, inviting customers to visit their laboratory for repairs and technical consultations via sergio@proyecto4.com. The store also highlights customer reviews and offers promotions like Yaesu Cashback, providing savings up to 100€.

The resource details the construction of a 6-meter _Moxon_ antenna, presenting two distinct versions: one horizontally polarized for 50-51 MHz CW/SSB and another vertically polarized for 52-54 MHz FM. It specifies the use of 5/8 inch OD and 1/2 inch OD aluminum tubing, with 3/8 inch OD solid aluminum for corners, and provides a comprehensive material cutting schedule. The design aims for robust, portable construction, with all materials costing under $100. Detailed drawings and EZNEC models are referenced for precise dimensions and assembly, ensuring accurate element spacing and impedance matching. The EZNEC model for the H-POL version predicts a gain of **11 dBi** and a front-to-back ratio of **25 dB** at 50.5 MHz, while the V-POL version shows a gain of **6.7 dBi** and a front-to-back ratio of **36 dB** at 53 MHz. The article includes practical SWR measurement advice, noting the impact of coax length and loss on analyzer readings. Field tests during a tropical storm demonstrated the antenna's durability and performance, yielding numerous contacts across significant distances, including California, Colorado, and Texas, on SSB and PSK.

The **HFRadioSales.au** resource provides a commercial outlet for amateur and commercial radio operators seeking HF SSB equipment and related services. It focuses on the Australian market, offering new and refurbished transceivers, antennas, tuners, and a wide array of spare parts for brands like Codan, Barrett, and Qmac. The site details its role as a licensed dealer for new Barrett Communications and Codan radio and antenna systems, including specific models such as the Barrett 4050, 2050, and 950, and Codan Envoy and NGT series. This platform supports various applications, including vehicle, 4WD, outback, marine, and base station setups, catering to networks like HF Radio Club, VKS737, and RFDS. It also features commercial-grade antennas from Bushcomm, such as the BBA100C and SWC100, available for fast shipping from their Queensland warehouse. The site includes an FAQ section with general information on mobile HF communications in Australia and timelines for specific transceiver models.

A 100Ft wire antenna for the top meter band

This QRZ.com callbook entry by DL6GD details the construction and performance of a **40m/80m Morgain folded dipole antenna**. The resource includes a schematic diagram, construction photos, and tuning notes. The antenna, with a total length of **20.30m**, was mounted at a height varying from 4m to 6m above ground. Construction utilizes 0.75 sq mm transparent insulated copper wire, with Plexiglas spreaders (5mm thick, 70x10mm) spaced at 25mm intervals, secured with hot glue. A waterproof junction box houses the feedpoint and balun. Tuning involved adjusting wire bridges for resonance on each band. On 80m, an SWR of **1.1:1** was achieved at 3.657 MHz, with an SWR of 2.7:1 at 3.580 MHz and 2.5:1 at 3.755 MHz, yielding a bandwidth of 175 KHz. For 40m, an SWR of **1.1:1** was measured at 7.100 MHz, with 1.5:1 at 7.000 MHz and 1.3:1 at 7.200 MHz, providing a 200 KHz bandwidth. DL6GD notes that 80m tuning exhibits slight height sensitivity, while 40m tuning is less affected by height or 80m adjustments. Long-term observations from 2014 and 2022 document SWR degradation due to environmental factors like spiderwebs and ice accumulation, which can cause HF-conductive paths between elements. DXZone Focus: Callbook Entry | 40m/80m Morgain Dipole | SWR Measurements | 20.30m Length

Over 1,000 stations in approximately 60 countries were worked using this modified twin-lead folded dipole, demonstrating its effectiveness with just 4 watts on 20 meters. This design, adapted from an ARRL Handbook concept, eliminates the shorting strap found in traditional folded dipoles, simplifying construction while maintaining performance. It utilizes readily available 300-ohm TV antenna feeder ribbon, making it a cost-effective solution for radio amateurs. The antenna's robust construction allows it to handle up to 100 watts without issues, even without a **balun**. The inclusion of a variable trimmer capacitor at the stub provides flexibility for tuning across different frequencies within a band, a practical feature for operators using transceivers like the Icom 735. Formulas are provided to calculate the precise dimensions for any desired operating frequency, enabling customization for various **HF bands**.

The NCDXF/IARU International Beacon Project operates a worldwide network of 18 high-frequency radio beacons, continuously transmitting on 14.100, 18.110, 21.150, 24.930, and 28.200 MHz. These beacons, initially launched in 1979 with a single station and expanded to the current 18-beacon system in 1995, provide reliable signals for both amateur and commercial users to assess current **ionospheric propagation** conditions. The system's design, construction, and operation are managed by volunteers, covering hardware and shipping costs. The resource details the evolution of the beacon network, including the transition from Kenwood TS-50s transmitters to Icom IC-7200 radios with a new controller design implemented in 2015. It explains how listening for these 100-watt signals, transmitted to vertical antennas, allows operators to determine band openings and optimal propagation paths globally. The content also references three QST articles providing historical context and technical specifics of the beacon project. Practical information includes methods for identifying transmitting beacons via a schedule or specialized software like FAROS and Skimmer, which integrates with the **Reverse Beacon Network** for automated monitoring.

Presents a QRP AM/CW transmitter project specifically designed for the 10-meter band, utilizing a crystal oscillator and a collector-modulated AM oscillator. The design employs a 2N2219(A) transistor in a Colpitts configuration, generating 100 to 350 mW of RF output power depending on the 9-18 Volt supply voltage and modulation depth. Frequency stability is maintained by a 28 MHz crystal, with fine-tuning possible via a Ct1 trimmer capacitor for approximately 1 kHz adjustment. The resource details the RF oscillator stage, implemented with a 2N2219 NPN transistor, emphasizing frequency stability and low power dissipation. It also covers the amplitude modulation stage, managed by a 2N2905 PNP transistor, which impresses audio information onto the carrier. Selective components (C3, C4, C7, C5) enhance voice frequencies within a +/- 5 kHz bandwidth, and modulation depth is controlled by R2 and R3. The project includes a 3-element L-type narrow bandpass filter (Ct3, L3, C10) to suppress harmonics and ensure a clean output signal. The project provides a complete schematic diagram, a comprehensive parts list including specific capacitor, resistor, and inductor values, and construction notes for the coils (L1, L2, L3). It also offers practical advice on enclosure requirements, suggesting an all-metal case or a PVC box with graphite paint for RF shielding. Operational parameters such as current draw (27mA@9V to 45mA@16V) and input impedance (50 Ohms) are specified, alongside guidance on antenna matching and the importance of a valid amateur radio license for 10-meter band operation.

The ZS6BKW multiband antenna, an optimized variant of the classic G5RV, features a 102-foot (31.1 m) horizontal span and a 39.1-foot ladder line matching section. This design, derived by G0GSF (formerly ZS6BKW) in the early 1980s using computer programs and _Smith charts_, aims for improved SWR across multiple HF bands compared to its predecessor. Construction details specify Wireman 554 ladder line and #14 AWG THHN copper wire for the radiators, with precise instructions for determining the velocity factor (VF) of the ladder line using an antenna analyzer or dip meter, ensuring accurate physical length for the matching section. The radiator length is electrically 1.35 wavelengths for the 20-meter band, requiring careful trimming during tuning. Field measurements with an _AIM-4170C_ analyzer by KI4PMI and NC4FB demonstrated good SWR curves and bandwidth on 6, 10, 12, 17, 20, and 40 meters. The antenna was deemed unusable on 15 and 30 meters due to very high SWR, but an LDG AT-100PRO autotuner successfully brought 6 and 80 meters into tune. Contacts were made on 80, 40, 20, and 17 meters, including a **17-meter** contact to Spain. EZNEC models for 80-6 meters are provided, along with an AutoEZ model by AC6LA, which predicted good SWR for 80-10 meters. W5DXP's modifications for an all-band HF ZS6BKW are also referenced.

A magnetic loop antenna working from 30 to 15 meters with 100W

Demonstrates how to construct an automatic band decoder, moving beyond manual selector switches for antenna and filter control. It addresses the challenge of varying band data outputs from different transceivers: Icom rigs provide voltage values, Yaesu rigs use Binary Coded Decimal (BCD), and Kenwood rigs lack direct band data output. The resource highlights a clever solution utilizing logging software like _CT (K1EA)_ and _DX4WIN_ to emulate Yaesu's BCD output via a PC's printer port, making the decoder compatible with any rig. The author details experiences building decoders based on designs by Bob _K6XX_ and Guy _ON4AOI_, noting K6XX's simple TTL chip design and ON4AOI's more comprehensive, opto-isolated unit capable of controlling ten outputs and bandpass filters like the _Dunestar_. It also references a _W9XT_ board design, which Steve Wilson, G3VMW, modified with BD140 transistors for source drivers, emphasizing safety. The author successfully cased an ON4AOI-based decoder in an old modem case, connecting it to an FT1000MP or a PC printer port to drive remote relays and a Dunestar Band Pass Filter.