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A new perspective on the analysis and design of this popular antenna element. By Karl-Otto Muller, DG1MFT

*One single page* gives you an immediate overview of current shortwave propagation conditions at your location.

The Flower Pot Antenna project details a portable dual-band antenna primarily operating on 10 meters, with secondary resonance near the 30-meter band. Construction involves winding RG58 coaxial cable uniformly around a large plastic flower pot, approximately 70cm high with a 60cm top diameter. The design eliminates the need for radials, contributing to its compact and lightweight nature. Key construction steps include soldering the inner conductor to the shield at one end of the wound cable and connecting the wound cable's shield to the rig cable's inner conductor at the base. An LC network, comprising a variable capacitor (0-200pF) and an inductor (10 coils, 5cm diameter, 2mm wire), is inserted between the wound cable's inner conductor and the rig cable's shield. Tuning is performed with an antenna analyzer, adjusting cable length and the variable capacitor for optimal impedance on 10 meters. The antenna performs effectively when installed horizontally.

A 3 band dipole for 10 15 and 20 meters band, easy to build, and that can be easily setup in any occasion, inclunding field days or portable operations

A 20 and 40 meter vertical on Autopilot by K6MHE PDF File

Download this color US ham radio band-plan in PDF format edited by ARRL

A 3 Element Mono-band Yagi for 20 meters by Kees Wiegers, PA5CW (ex-PA3BHS)

A **mobile HF multiband antenna** project details the construction of a center and top-loaded design, optimized for 10 through 80 meters. This antenna incorporates a capacity hat positioned high on the whip for enhanced efficiency, differing from commercial bugcatcher designs. The coil construction prioritizes high Q and minimal loss through an air core, open spacing, and heavy gauge wire, contributing to its lightweight nature and suitability for portable operation with a proper counterpoise. Band switching is achieved by manually moving a jumper plug to various tap points on the coil, allowing for operation across multiple bands, with 17m being resonant when the coil is bypassed. The design, a result of nine months of experimentation by N1LO, includes detailed instructions for modifying a Hamstick antenna base, creating a jumper wire, and assembling the capacity hat using stainless steel wire and silver-bearing solder for robust connections. The loading coil utilizes nylon grommet strips around a PVC pipe for an air-core winding, ensuring high efficiency. Tap sockets are fashioned from silver-plated 5-way binding posts, providing low-resistance RF joints for band selection. Guidance on tap point determination emphasizes using an antenna analyzer like the MFJ 259B or 269 to achieve resonance, especially on 40m and 80m where feedpoint resistance can be low. The document also covers the installation of monofilament stays to maintain antenna uprightness at highway speeds, with specific attachment points for stability.

The 80-meter loop antenna, measuring 86 meters (282 feet) of wire, effectively operates across 8 HF bands from 80 through 10 meters, despite its length being a compromise for specific bands. This design prioritizes a "low enough" SWR across multiple bands, aiming for lower SWR values on higher frequencies due to increased feedline losses. A 200-ohm feedpoint impedance provides a workable SWR on every band, with feedpoint impedances ranging from 100 ohms for lower bands to 300 ohms for higher bands. Radiation patterns for the 80-meter loop, mounted at 15 meters high, show a maximum gain of 7.6 dBi at a 90-degree takeoff angle on 80 meters, and up to 12.9 dBi at a 10-degree takeoff angle on 12 meters. This configuration supports regional contacts on 80 meters and provides good DX performance on higher bands. Practical construction notes emphasize using robust supports like trees, ensuring wire slack with _egg insulators_ for wind resilience, and employing an oversized 2 kW 4:1 _balun_ to safely handle higher SWR conditions, even with 100W transceivers. Feedline losses are minimized using _LMR-400_ coax or ladder line, with power transfer efficiency between 80% and 95%. Antenna simulations were performed using _xnec2c_, and the provided NEC file is compatible with other NEC2 derivatives. The antenna is tunable on 6 of 8 bands with an internal ATU and all 8 bands with an external autotuner like the LDG AT-200 Pro.

Pictures of 2.4 Ghz antennas, JN1GKZ S-band homemade antennas

HF multiband mini delta compact and easy assembling antenna that cover from 20 to 10 meters by GM3VLB

The _Morgain_ antenna for 40/80 meters is a straightforward and cost-effective wire antenna design, requiring careful tuning for optimal performance across two bands with low SWR. Construction involves creating 12 cm PVC spacers with three holes for wire insertion, along with larger terminals for anchoring and connector housing, which should be sealed with silicone. The provided measurements detail the specific lengths for the antenna elements, crucial for achieving resonance on both 40m and 80m bands. Tuning the Morgain antenna necessitates fabricating four wire segments with pins to temporarily connect and adjust the bridging points symmetrically for both 40m and 80m. This iterative process, though time-consuming, ensures the antenna functions effectively for decades once the precise connection points are soldered and protected. The design emphasizes ease of construction and long-term stability, making it a practical solution for hams seeking a dual-band wire antenna.

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

IARU band plan comparagraph

Homebrew a j-pole 2mt and 70 cm antenna project. Make it cheap. This article includes homebrewing instructions, parts lists, tools needed and printable documentation.

The multi-band trapped dipole is resonant on approx 3.7, 7, 14, 24 7 28.5 Mhz. The overall top length needs to be approximately 32.9 Meters

Concentric Open Loop Antenna Fed Off-Centre similar to the cobwebb antenna but resonating on 20-17-15-10 meters band

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

40 meters band Delta loop antenna plan that is vertically polarised

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.

Demonstrates the construction and on-air performance of the _NB6Zep_ antenna, a modified 20-meter Extended Double Zepp design optimized for multi-band operation from 40 through 10 meters. The resource covers basic design principles, including dimensions of 66 feet horizontal and 5 feet vertical elements, and specifies open ladder line or TV twin lead for the transmission line. It details material selection for low-cost wire antenna construction, such as 18 AWG wire for the legs and ceramic or plastic insulators, along with practical tips for soldering connections and insulating against moisture. The author, NB6Z, shares insights from extensive _EZNEC_ modeling to optimize the antenna's total length for a 40-meter half-wave dipole footprint and feed line length for direct tuner connection. The article presents field results, including successful _PSK31_ contacts from Oregon to the East Coast on 40 and 30 meters with 50 watts, even at a low height of 6 feet. It provides detailed performance characteristics for each band, noting the _NB6Zep_'s highest gain (over 3 dB) and sharp, medium-angle lobes on 20 meters, which yielded strong DX reports to locations like Korea, Japan, and Argentina. For 17 and 15 meters, it describes a butterfly-like pattern with broad lobes, while 12 and 10 meters exhibit narrow, directional lobes in an "X" configuration. The author also shares personal experiences operating successfully for over a decade in an antenna-restricted environment using the NB6Zep and other stealth wire antennas.

Radio sales to over 60 countries, source for all communication equipment, individual hobbyists, professionals and dealers.

Delta Loop Antenna for 15m band. This antenna is made for operating from outdoors, mainly from mobile shack. Drive to a parking you like, then build it up. Just half an hour later, you can enjoy slightly better gain than normal dipole.

The cobweb antenna it is basically a 5 band antenna comprising of 5 full half wave dipoles for each band - between 10 meters and 20 meters, the antenna is also resonant on 6M and can be modeled even for VHF frequencies.

This design represents the smallest practical antenna for Oscar-13 mode-S. Perfect beacon reception at all times is possible, and acceptable SSB even at 43,000 km range.

Simplified U.S. frequency allocations table by K8ZT

This improved multiband trap dipole introduces a new trap design and a change in trap location. The antenna features double-coaxial-cable-wound traps having lower reactance and a higher quality factor (Q) than earlier coax-cable traps by W8NX

Presents a detailed construction guide for a 2-element _Moxon rectangle_ antenna optimized for the 10-meter band, designed by L. B. Cebik, W4RNL (SK). This resource demonstrates how to build a compact beam antenna using readily available hardware store aluminum tubing, fitting within a 12-13 foot width. It highlights the antenna's performance characteristics, including a gain comparable to a 2-element Yagi (11+ dBi) and a front-to-back ratio exceeding 20 dB between 28.3 and 28.5 MHz, with an SWR below 2:1 across the entire band. The design emphasizes direct 50-ohm coax connection without a separate matching system, though a 1:1 choke _balun_ is recommended. The guide provides practical advice on element construction, corner fabrication using L-stock or radius-bent tubing, and the critical side-to-side length adjustment for SWR optimization. It details the feedpoint assembly using a chassis-mounting coax connector and discusses element-to-boom plate options, including spar varnished plywood or LE plastic. The author's experience with a test model on a 20-foot mast confirms stable feedpoint characteristics and excellent performance even at lower heights. The document also includes insights into the antenna's free-space azimuth patterns, noting a broad forward lobe and significant front-to-back rejection. It contrasts the Moxon with traditional Yagis, positioning it as an effective, home-buildable alternative for compact sites or _Field Day_ operations, particularly beneficial during periods of increased 10-meter activity.

Multiband Center-Loaded Off-Center-Fed Dipole (CL-OCFD) antenna that work on 80m 40m 30m 20m 15m 10m. The Center-Loaded Off-Center-Fed Dipole (CL-OCFD) antenna, developed by Serge Stroobandt, offers a versatile solution for amateur radio enthusiasts, covering multiple HF bands (80, 40, 30, 20, 15, and 10 meters) without the need for an antenna tuner. This innovative design utilizes a capacitor for resonance on the 80-meter band and a resistor to manage static charges. The CL-OCFD enhances bandwidth and simplifies operation, making it a significant advancement on OCF Dipole design.

EI7BA Multiband Cubical Quads projects, includes two elements quad antennas for 10 12 15 17 20 meters band. Performance considerations, detailed pictures and construction notes.

Bandplans for region 1 in pdf format by DARC

The Inverted L antenna is a versatile and efficient design suitable for small gardens, allowing amateur radio operators to operate on multiple bands. This project outlines the construction of a 5-band inverted L antenna, which can cover HF bands effectively. The design is particularly advantageous for those with limited space, as it requires minimal ground space while providing good performance. The antenna can be easily constructed using common materials, making it accessible for both beginners and experienced hams. In this guide, GM0ONX shares detailed instructions on how to build the inverted L antenna, including dimensions and tuning tips. The project emphasizes the importance of proper installation and grounding to ensure optimal performance. Additionally, it discusses the antenna's compatibility with various transceivers and the potential for portable operation. This resource is ideal for hams looking to enhance their station with a multiband antenna that performs well in limited space.

Multi-band centre-fed antenna capable of very efficient operation on all HF bands, specifically designed with dimensions which allow it to be installed in gardens and other open spaces which accommodate a reasonably-straight run of 31.1m (102 ft) for the flat-top standard model.

Indoor multiband dipole with EZNEC data files for simulation and analysis. Includes details on construction, tuning, SWR plots, and software usage. This page includes two different dipoles, a first version for 20-10 meters and an extended version covering 40-10 meters allowing a full coverage of most used ham radio HF Bands.

Free Band modification for the Yaesu VX-6R

A simple dipole built for two-band operation can be used for portable use and operate 20 and 40 meter bands

Article by DK5WL describes a multi-band DX antenna for the 160m-40m amateur radio bands with low visibility but great performance for long distance communication.

This project uses a widely available IRF510 MOSFET, work on HF 80, 40, 30, 20 and 17 meter bands

Build a Multi-Band Mono Delta Loop for 40, 30, 20 and 15 Meters.

This PDF File desscribes how to homemade a multi-band end-fed trapped wire antenna resonating on the low bands of 160 80 and 40 meters. Contains trap design instructions and some construction tips.

This article addresses the subject of obtaining the best signal transfer from an antenna to the typical 50-ohm receiver input over a wide frequency range, with emphasis on medium-wave (500 - 2000 kHz), encompassing the standard AM broadcast band and the 160-m amateur band.

This Multiband Cubical Quad antenna a boomless Quad design with glass-fibre arms and a single coax wire connected to a remote antenna switch. This aerial work on 8 bands and has a 60-degree beam width. Despite achieving critical technical requirements, the antenna's three-dimensional structure presents obstacles, such as installation issues on fixed towers and risk of frost damage. The spider framework is built of stainless steel, with a compact 18-inch boom and strong angle iron arms. Tait use a variety of methods to fasten element wires and suggests placing them on the outside of the spreaders for improved insulation. The use of nylon twine or parachute cord between key attachment points allows for adjustable separation between pieces.

Wire antenna for 10-15-20-40-80 meters band, with many drawings and description in spanish

A loopy loop loaded vertical antenna operating range 7.0 to 7.3 MHz by S. C. Chuck Smith, WA7RAI

The document is a PDF detailing the construction of the DBJ-1 VHF-UHF Dual Band J-Pole antenna for amateur radio use. It provides instructions on how to build a high-performance dual band base antenna for VHF and UHF bands using a single feed line for less than $10.

The ZS6BKW multiband HF antenna, a design by ZS6BKW (G0GSF), functions effectively on multiple HF bands without requiring an Antenna Tuning Unit (ATU) for 40, 20, 17, 12, 10, and 6 meters. This antenna, approximately **27.51 meters** (90 feet) long with a 12.2-meter (40-foot) open-wire feeder, is a direct descendant of the _G5RV_ but offers superior multi-band resonance. It can be deployed as a horizontal dipole or an inverted-vee, with the latter requiring only a single support and maintaining an apex angle of at least 90 degrees to prevent signal cancellation. Performance data, recorded with an MFJ Antenna Analyser, indicates SWR values of 1:1 on 7.00 MHz (40m) and 14.06 MHz (20m), with SWR below 1.3:1 on 17m, 10m, and 6m. While primarily designed for these bands, the antenna can be adapted for 80m, 30m, and 15m with an ATU, preferably at the balanced feeder's base. The use of 450-ohm twin-lead for the feeder is recommended over 300-ohm for improved strength and reduced losses, especially in adverse weather conditions. This design, originally published in _RadCom_ in 1993 and featured in Pat Hawker’s "Antenna Topics," provides a compact and efficient solution for HF operation, particularly for those with limited space or resources.

The Petlowany Three-Band Burner is a simple, low-cost, trapless short vertical antenna which amazingly works on three HF bands (20, 15 and 10 meters). This web page contains pictures, performance data, and enough construction details so you can homebrew your own.

The H-Pole is a vertical multiband wire antenna for 160-10 meters bands

17 Meter 3 element TA33 junior mono band yagi antenna conversion project by K6TC

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.