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This halo antenna was built to have an omnidirectional coverage while working in VHF contests.

Homebrew a 2 meter 1/4 wave vertical antenna for the 146 mHz ham radio band

An homemade portable vertical antenna with a trap near the mid point of the main element. The trap is made with 42mm diameter PVC pipe with 9 turns of wire on it

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.

Constructing a Lindenblad antenna for 137MHz NOAA satellite reception involves specific design considerations for optimal performance. The resource details the use of 4mm galvanised steel fencing wire, 300-ohm television ribbon cable, and wood/plastic components for the antenna structure. Key dimensions for a 137.58MHz-resonant antenna are provided, derived from the ARRL Satellite Handbook, specifying s, l, w, and d as 42, 926, 893, and 654mm respectively. The antenna is designed for Right Hand Circularly Polarised (RHCP) signals, requiring the four folded dipole elements to be tilted clockwise by 30 degrees. A significant aspect covered is impedance matching between the antenna's 75-ohm impedance and a typical 50-ohm receiver input. A twelfth-wave matching transformer, constructed from 117mm sections of 50-ohm RG-58 and 75-ohm RG-59 coax with a 0.66 velocity factor, is described. The article also addresses coaxial cable and connector selection, recommending 75-ohm Type-N connectors for RG-6 cable in professional setups and F56/F59 connectors for general use, while strongly advising against PL-259/SO-259 connectors for VHF. Strategies for mitigating Radio Frequency Interference (RFI) are discussed, including antenna placement to shield from local TV transmitters and the use of commercial or DIY band-pass filters, such as cavity resonators or helical notch filters, along with ferrite chokes on coaxial cables. Antenna orientation is explored, noting the Lindenblad's 'cone of silence' directly overhead and its maximized sensitivity towards the horizon. An experimental vertical tilt of 90 degrees is presented as a method to improve overhead reception and reduce interference from strong horizontal signals, particularly relevant in high RFI environments like the Siding Spring Observatory site.

A 46ft multi-band antenna for small gardens that works on 80m. An excellent DX performer and is an ideal replacement for your half size G5RV by G7FEK

A project for a portable antenna for amateur radio satellite reception, for 2 meters and 70 centimeters bands

"Low profile antennas for the ""ham"" radio user"

The Homebase10 is a simple to make wire halo antenna for 10m (28MHz) built using parts available from the local DIY store.The resulting antenna is very effective on 10m despite its small size and light weight.

Crossed-Field Antennas and E/H Antennas

A helix will work in the normal mode when the diameter and pitch of the helix is less than 0.1 Lambda

A Crank up mast pipe by Bob Bruninga

A circular waveguide calculator for designing cantennas include source code and windows executable by lincomatic

The idea of using a low mount dipole, enhanced with reflector wires directly beneath the dipole, on the ground, appears to be a very good approach to creating an NVI specific antenna for local HF operation.

The W2DRZ Antenna controller system is a low cost but effective system to monitor and control an antenna system's position.

Excel sheet containing technical comparisons of commercial HF portable antennas compiled by ON4SKY. Includes pictures, manufacturer, db gain, band coverage, F/B ratio, price, weight and dimensions.

Article by Ed Bathgate, N3SDO as published in CQ VHF Magazine July, 1988

Loop Antenna Starter Kit contains detailed plans for building the MTM Scientific, Inc. loop antenna from scratch.

A delta loop antenna for 17 meters band include eznec antenna model file

Easy Quad calculator, enter center frequency to get a quad antenna size

A compact Beam Antenna That Can Be Built At Home. Made with lightweight wooden "X" frame with two folded and linear loaded wire elements. The two elements are approximately a half-wave each.

Launching a balloon or kite supported tall vertical or protracted inverted L.

This page describes a simple way to determine the main RF characteristics of a Wifi (IEEE802.11b/g wireless LAN) antenna.

ARRL index of document about trapped antennas and notes on traps usage

Article on rhombic antennas, radiaton patterns, disvantages, and more info on rhombic aerials

This doubet antenna is a half wave dipole antenna easy to build, in french

German article on the multiband dipole by DG0KW. This antenna can be configured for several bands and can work in 3 or 4 bands mode. Can be used in restricted space lots.

Presented here is a high-performance, circularly polarized omni-directional antenna that is easy to build, easy to tune, inexpensive, and will work all the mode J Low Earth Orbit (LEO) satellites

Presents the design and construction of the OK2FJ Bigatas, a portable, automatically tuned vertical antenna covering 80 through 10 meters. It details two distinct control systems: one utilizing BCD band data from Yaesu FT-857/897 transceivers, and another employing voltage level sensing for the Yaesu FT-817. The resource provides specific instructions for building the antenna's radiating element, loading coil with switchable taps, and the control circuitry, emphasizing the use of readily available components. The article outlines the physical construction of the antenna, including the use of duralumin tubes for the radiator and a PVC tube for the coil form. It specifies coil winding details, tap points, and the integration of radial wires for ground plane operation. The control electronics section provides schematics and component lists for both the BCD decoder (using a 74LS42 IC) and the voltage comparator (using an _LM3914_ bargraph driver), enabling rapid, automatic band switching without the minute-long tuning delays common in other systems. Crucially, the antenna achieves rapid band changes, with typical SWR values centered on common operating segments, such as **3.7 MHz** for 80m SSB. It also discusses modifications for CW operation on 80m and the trade-offs between antenna efficiency and full-range automatic tuning on higher HF bands, where manual adjustment of radiator length is suggested for optimal performance on 15m, 12m, and 10m. The resource includes construction photos and a discussion of cable requirements for reliable operation.

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 resource details the computer-optimized design of the _ZS6BKW_ multiband dipole, an evolution of the classic _G5RV_ antenna. It begins by referencing the original 1958 RSGB Bulletin article by Louis Varney G5RV, explaining the operational principles of the G5RV's flat-top and open-wire feedline on 20m and 40m, noting its impedance transformation characteristics for valve amplifiers of that era. The article then transitions to the rationale for optimizing the design for contemporary solid-state transceivers requiring a 50 Ohm match. The core of the project involves using computer modeling to determine optimal lengths for the flat-top and matching section, aiming for a VSWR of less than 2:1 on multiple HF bands. It discusses the process of calculating feedpoint impedance based on antenna length and frequency, referencing professional literature from Professor R.W.P. King at Harvard University. The analysis also considers the characteristic impedance (Z(O)) of the open-wire line, identifying a broad peak of adequate values between 275 and 400 Ohms. Specific design parameters for the improved ZS6BKW are presented, including a shorter flat-top and a longer matching section compared to the original G5RV, with a velocity factor of 0.85 for the 300 Ohm tape. The article confirms acceptable matches on 7, 14, 18, 24, and 28 MHz bands when erected horizontally at 13m, and also discusses performance in an inverted-V configuration, noting frequency shifts. The author, Brian Austin ZS6BKW, emphasizes the antenna's suitability for modern 50 Ohm coaxial cable without a balun.

A simple base loaded quarter wave vertical, which can be used on a car or portable by G3YCC

Built around a 1/2" pvc frame, Larry's 6 meter moxon antenna is made from #8 aluminum ground wire

Double bazooka antennas

This is a simple calculator for solving the antenna wire catenary between to end points given the design wind speed, mass per unit length of the wire, wire diameter and Gross Breaking Strength of the wire.

HF pedestrian operation using loop antennas by PY1AHD

Build your own home made Antenna Analyzer with an arduino micro, or a cheeper one with a pic processor

Improved Helical Antenna Design for 802.11b WLAN by PA0HOO

F6CHT plan for a multiband yagi antenna that covers 6 to 30 meters band in french

Overview, summary, tutorial about the log periodic antenna or aerial used for wideband RF antenna applications

W5JGV antenna tuner for 150 - 500 Khz band

Simple implementation of the ARRL Antenna Book design equations for the axial-mode helical antenna.

Remote Control Antenna Switch made with two circuits board

Vortex Antenna Systems, radio communication antenna aanufacturer and supplier of antenna related hardware. Ham radio HF and VHF Antennas, antenna parts, mast and mounts.

A ranking of receiving antennas based on noise being evenly distributed in all directions. These rankings are most accurate in the frequency range of AM broadcast, 160 or 80 meter bands

Solution to your OEM needs and can meet your design or vended antenna requirements for antennas from 400MHz to 10 GHz.

A 2-way remotely operated HF antenna switch, based on an idea supplied by G3YEU

Tombone VHF antenna for 146 MHz ad designed by YB8EIP

A very simple Eh antenna for 11 meter, drawings in english and italian.

An analysis of the cebik dipole and other small limited space dipoles fed with open wire ladder line.