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Also known as Magnetic Loop Antennas, by AA5TB. Excellent article on construction tips and tecniques of a Small Loop antenna

A well documented article on a small magnetic loop antenna for the 40 meters band

A multi band version of the EH antenna by Emilio S. Campus IS0IEK

Multiband no trap no gap antenna. This Antenna is a small wonder, easy to build and allow you to work all HF spectrum with your TRX and it's internal ATU.

This note describes a relatively small, but efficient, loop antenna initially created for portable operation. With suitable modifications, it can be adapted for fixed station use. In this age of CC&Rs, an antenna similar to this may very well be the answer to your problems. Have a look, be inspired, get out the torch / soldering iron and create your own version!

2 element reversible verticals, small footprint, big results.

Based on DL6UW Yagi antenna's design-formula The forward gain is 13.6 dBi (about 11.5 dBd) and it's pretty small, about 1,5 m in length

A small portable antenna tuner for HF and VHF bands by ON6MU

A small company that specializes in antennas and accessories for radio hobbyists who enjoy DXing the AM broadcast and LW bands

An Active antenna designed for VLF and shortwave radio reception. A small antenna capable of excellent performances on low bands, made on a copper plate and introductio to active antennas.

This transceiver was conceived as a power-efficient, small, lighweight unit to be carried in the backpack, along with antenna and battery.

Loop antennae have been used from ELF to UHF since the beginning of radiocommunications. At low frequencies, the main problem for loop antennae is to have enough sensitivity; the antenna being very small respect to the wavelength the collected energy is also small. To increase the output level the loop may be made resonant, so loosing it%u2019s intrinsic aperiodic characteristics.

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.

An cheap, easy to construct and not too visible antenna for the low bands

Article on radiation patterns of small loops, equivalent circuits of loop antenna, small loops as receiving antennas, ferrite loops

This magnetic loop is 78cm diameter, with the smaller Hertz loop for tuning. Feeding is by gamma match.

For radio amateurs seeking compact and efficient antenna solutions, particularly for restricted spaces or noise reduction, HF loop antennas present a viable option. This resource compiles several articles from the ARRL, detailing the theory, design considerations, and practical construction of various loop configurations. Topics include small transmitting loops, receiving loops, and multi-band designs, often emphasizing their performance characteristics such as directivity, bandwidth, and impedance matching. The collected articles provide insights into the comparative performance of different loop geometries, such as circular versus square loops, and discuss the impact of conductor size and tuning methods on efficiency. Practical applications are explored, including their use in portable operations, stealth installations, and urban environments where noise mitigation is critical. The content often includes construction diagrams, parts lists, and performance data derived from modeling or field tests, enabling hams to replicate or adapt the designs for their specific operating conditions.

The WT0G crazy W dipole, a solution for 160 meter operations

This antenna was described by Bill, G4KIH in Sprat 52 and is actually a G5RV modified to fit into a small space.

Small & practical DIY inverted U antenna. This design worked very well during the 2017 CQWW 160M SSB contest.

A small antenna for limited space / lanai use.

Alan yates vk2zay's ham radio website, homebrew construction, general electronics, high voltage experiments, amateur rocketry, and general geek stuff

Although a magnetic loop antenna(aka small loop antenna) is very compact, its efficiency is close to a half-wavelength dipole if carefully built.

An active receiving antenna for 10 KHz to 20 MHz, a very small sized antenna with excellent performances in noise to signal ratio.

Homebrew a compact yagi antenna for 14 Mhz suitable for those with small plots based on a design by AB4GX

The G7FEK Multi-Band Nested Marconi Antenna, a small, efficient all-band antenna.

A small random wire antenna tune that can tune from 40 to 10 meters bands.

Experiments on HF antennas for restricted spaces. In this article author experiments antennas for 80-10 meters band having just a very small garden and several restrictions. Basic antennas consists of laded multiband dipoles and fan dipole antennas

Carry a small stock of new and reconditioned parts for both rotators and control boxes for the following makes: CDE/HYGAIN , YAESU , STOLLE.

A 2 element small footprint 40 meter phased, reversible, downsized quad array antenna.

A project of a small antenna, just 50 cm for the 7 MHz band. An EH Antenna plan for the 40 meters band

Article about small magnetic loop antennas with notes on realization of magnetic loops for several HF bands and the six meter band

The N3UJJ multi band cage dipole antenna project thay can fit a small property

A small antenna tuner for 14 MHz

This project produces a sturdy tripod for small vertical antenna support using readily available electrical metal tubing (EMT) or conduit

A small sized and very cheap antenna project that allow you to work on WARC bands with a total gain very close to the dipole in both bands. On 12 meters is a normal dipole, while on 17 is a trapped dipole. Article in Italian

Receive-only loop antennas have some nice response characteristics that make them ideal when used for reception of skywave signals.

Picture and reference links for STL Small tumed loops antennas by DJ3TZ

A system designed to automatically tune small transmitting magnetic loop antennas, particularly beneficial for **contest operations** where rapid frequency changes are common. The core of the system involves a PC-based control application, AutoCap, written in C#, which monitors antenna SWR via an external meter and commands a motor interface to adjust the loop's variable capacitor. The software is compatible with Windows and Linux via the Mono framework, offering a graphical user interface for monitoring system status, SWR, power, and motor commands. Key components include one or more magnetic loop antennas equipped with DC or stepper motors for capacitor adjustment, an SWR meter with data output (such as the Telepost LP-100A or a homebrew serial/USB SWR meter), the AutoCap PC software, and a motor interface. The most effective motor interface utilizes an **Arduino-based controller** with custom firmware, providing precise control over both simple DC motors and stepper motors, and supporting features like motor braking for finer adjustments. The system allows for configurable SWR thresholds, pulse widths, and motor effort settings to optimize tuning speed and resolution. Optional radio integration provides frequency hints, enabling the algorithm to learn the relationship between motor actions and resonant frequency, thereby speeding up initial tuning responses. The software also supports antenna profiles, allowing operators to save and recall specific configurations for different loops, including accumulated frequency hint data.

Small antenna, what causes loss and how to increase radiation resistance in small antennas., A description of loss and radiation resistance.

G4ILO compares popular antennas for 2 metre band handhelds so as to see how much you lose using a small inconspicuous antenna or how much you gain by using a long antenna.

Hams have been putting stations in their cars since the Twenties. Today, there is great satisfaction in facing the challenge of installing a transceiver in our small cars and pick-ups, using somewhat inefficient antennas

Supplier of two-way radio products and accessories to large and small businesses, volunteer groups, radio amateurs and individuals. Transceivers, receivers, antennas cw keys based in London UK

HFRadio.US is a woman-owned small business that specializes in products for the HF market. We have our own line of broadband HF antennas plus other specialized products primarily for the Motorola Micom series radios.

A NEC Model Comparative Analysis of Physical Orientation and Performance. The small magnetic loop is a useful compromise antenna for limited space and portability. For this reason, the magnetic loop antenna is a practical high frequency antenna solution for the restricted space of apartment dwellers

Pictures and description of a SteppIr vertical antenna setup in a small backyard using DX Engineering radial plates.

A small dipole antenna installed inside a balcony. This linear loaded short dipole antenna has been designed at first for the 21 MHz and then adapted for the 20 meters band.

This is about Small Antenna types and their properties which can help choosing proper antenna for high-frequency wireless communications as: two-way radio, microwave short links, repeaters, radio beacons or wireless telemetry

The _Sci.Electronics FAQ: Repair: RFI/EMI Info_ document, authored by Daniel 9V1ZV, provides a detailed analysis of computer-generated RFI/EMI, focusing on its impact on radio reception. It identifies common RFI sources such as CPU clock rates (e.g., 4.77 MHz to 80 MHz), video card oscillators (e.g., 14.316 MHz), and even keyboard microprocessors, all of which generate square-wave harmonics across HF and L-VHF regions. The resource outlines a systematic procedure for pinpointing RFI origins, including disconnecting peripherals and using a portable AM/SW receiver with a ferrite rod antenna to localize strong interference sources. The document categorizes RFI mitigation into shielding, filtering, and design problems, offering practical solutions for each. It recommends applying conductive sprays like _EMI-LAC_ or _EMV-LACK_ to plastic casings of radios, monitors, and CPUs to create effective Faraday cages, emphasizing proper grounding and avoiding short circuits. For filtering, the guide suggests using line filters, ferrite beads, and toroids on power and data lines, and small value capacitors (e.g., 0.01 uF for serial/parallel, 100 pF for video) to shunt RFI to ground. It also discusses the use of bandpass, high-pass, low-pass, and notch filters on the receiver front-end or antenna feed to combat specific in-band noise.

A Simple Delta Loop Antenna for Smaller Vessels