Search results

A balun is a MUST for dipoles or similar antennas when they are feed with coaxial cables. Many hams connect the center conductor of the coaxial cable to one side of the dipole, and the shield to the other. Wrong!

How to build your own beverage antenna for 80-160 meters band by K5ZD

This 4m Slim Jim Antenna is cheap and easy to build yet it greatly out performs the more usual dipole due to its low angle of radiation. An SWR of 1:1 is obtainable across the 4m ham radio FM band with a simple adjustment.

This article describes a project of asymmetrical hatted vertical dipole, a portable antenna that can be used for field day operations, sota, campings or even for fixed installations. This is a freestanding 20-10m antenna that is really easy to build, easy to tune and relatively easy to carry.

How to build a super AM antenna, These plans have been used by many people, with good results.

Double Bazooka Antenna, a simple coax based and broad band antenna you can easily build

Backpacking, boating or mountaintopping ? Invest your time and pack this novel directional gain antenna on your next expedition

The Moxon Beam, introduced by L. Moxon (G6XN), is a compact 2-element Yagi featuring a radiator and reflector with reduced dimensions, approximately 75% the size of a full-size beam. This design utilizes bent element ends for capacitive loading, which is superior to inductive loading with coils, resulting in greater bandwidth and lower losses. DK7ZB details that while the gain is slightly lower (0.5-0.7 dB) than a full-size beam, the _Moxon_ offers an exceptional front-to-back (F/B) ratio of 30 dB or more on its design frequency, surpassing other 2-element beams. The article provides specific dimensions for building wire _Moxon_ antennas for bands from 30m down to 10m, and also mentions a 2-m-Moxon. Construction guidance includes using fishing rods for lightweight spreaders and an aluminum tubing spider for support. The resource highlights the utility of _Moxgen_ by AC6LA, a freeware program that simplifies Moxon beam design and generates EZNEC output files for further analysis and tapering modifications. DK7ZB emphasizes that the design frequency should be set at approximately one-third from the band's beginning to optimize SWR performance, as SWR tends to rise more significantly below the design frequency. The bandwidth for SWR < 1.5 is noted as sufficient for ranges like 28.0-28.7 MHz and 21.0-21.45 MHz when constructed with aluminum tubes, though wire beams exhibit a narrower bandwidth.

TX RX Systems Inc. offers a robust catalog of RF conditioning products, including **transmitter combiners**, receiver multicouplers, and various RF filters. Their extensive experience, spanning over 45 years in the RF and Land Mobile Radio (LMR) industries, underpins their specialized offerings. They provide solutions for in-building RF coverage, repeater systems, and general RF management, catering to the demanding requirements of professional radio communications. Their product line features **bidirectional amplifiers (BDAs)**, signal boosters, and cavity filters, essential components for optimizing radio system performance. The company emphasizes reliable solutions, leveraging decades of field-proven expertise in designing and manufacturing critical RF infrastructure. From duplexers to cell enhancers, TX RX Systems focuses on delivering high-quality RF components and integrated systems designed to ensure clear and consistent radio signal integrity across diverse operational environments.

Small, but growing, group of amateur radio enthusiasts, most of whom are within 90 miles of Atlanta, are interested in promoting the development of the branch of amateur radio known as QRP - building and operating low power transmitters, receivers and transceivers.

Building a cavity resonator for 144 MHz

A helpful guide to building your own beverage-type low noise receiving antenna for broadband use. Easy, do-it-yourself suggestions to optimize directional performance, even if you lack a farm to put it on.

Nowdays lots of people are putting up antennas to either beam in different directions at the same time or just to stack them and get a lower angle of radiation. Use this stackmatch to match you array.

Building an omnidirectionnal antenna for the 23 cm band, 1240 - 1270 Mhz

Build An Inexpensive Repeater Controller from a Basic Stamp 1 or 2 By Roger Cameron

6m (50Mhz) Long wire antenna There is another form of long wire antenna which provides uni-directional coverage and is easy to build. Description by Arnie Coro CO2KK

This document contains the detailed instructions to build a homemade lindenblad antenna using a twin-lead as dipole elements. This document contains 9 pages and includes a detailed construction sequence and some drawings to build this antenna for UHF and VHF ham radio bands

Paddles made from readily available materials, like double sided PC board material and cost almost nothing to build.

Homebrewing a mic boom headset for the Yaesu FT 897 and 857 transceivers

Make your own interface, two schematics for building an interface using the RTS line by N3UR

If your doing any home brewing gear for ham radio its a great idea to have a dummy load. This will to your radio be the perfect antenna...it will never radiate but your radio sees a perfect 50 Ohm impedance.

Original Tuna-Tin 2 QRP CW transceiver article by W1CER

SM5BSZ article on building VHF RF amplifiers

Building an Open Source Arduino APRS Tracker with LCD & GPS ( SVTrackR )

A sourge arrestor for PL 259 connectors. A voltage surge arrestor to limit the voltage that may come back down the wire or coax after there has been static build up

How to build a no tuner 80 meter, half wave wire antenna that takes full advantage of the phone portion of the band known as 75 meters.

Building a 2 metre 144MHz VHF Yagi beam antenna, designed for portable use.

The Collins 516F-2 is a heavy-duty power supply for the KWM-2/2A transceivers and the 32S-1,2,3 series of Collins transmitters.

Build this cheap and easy satellite downlink antenna

A javascript online calculator for popular wire antennas, from the standard easy to build flat-top dipole, to the inverted V dipole, but also the Quad Loop, and the equilateral delta loop antenna

A portable amateur radio station which the radio amateur can take when asked to go to an event which needs support with radio communication.

The resource details the construction of a **Hustler-compatible** HF mobile antenna mast, utilizing 1/2-inch copper water pipe and common hardware. It provides a bill of materials, specifying one 10-foot copper pipe, four 1/2-inch copper end caps, and 3/8-inch fine-thread hex bolts and nuts, totaling $8.75 for two masts. The construction process outlines preparing bolts by rounding their heads, drilling 3/8-inch holes in end caps, soldering bolts into caps, and then soldering these cap/bolt assemblies to 5-foot sections of copper pipe to achieve a final length of 54-1/4 inches per mast. The method emphasizes precise soldering techniques to ensure structural integrity and proper fit. The resulting masts are presented as functional alternatives to commercial units, with the author noting their performance is comparable to the "real thing." Installation tips are provided, including the use of braces connected to a trunk lid to mitigate stress on the antenna mount, contrasting this approach with WA8WTE's spring-based method. Photos illustrate the completed mast mounted on a vehicle, demonstrating practical application and support strategies for mobile HF operation, particularly with larger coils and longer whips at highway speeds.

How to build a simple WSPR beacon using the Raspberry Pi for the transmitter

An easy portable VHF antenna to build for ARES - RACES work is the 300 Ohm Twin Lead JPole antenna

Building a high voltage (5KV), variable plate capacitor (17 to 220pF)

Optimizing a G5RV or ZS6BKW multiband wire antenna for HF operation often involves addressing common SWR issues and understanding feedline characteristics. This resource chronicles the construction and performance evaluation of a G5RV, initially built for 80m, 40m, 15m, and 10m bands, by a newly licensed Foundation operator. The author details the selection of materials, including 3.5 mm stainless steel wire for the doublet arms and enameled copper wire for the open-wire feeder, and the initial decision to omit a balun based on common online information. The narrative highlights the initial disappointing performance, characterized by high receive noise and poor signal reports on 80 meters, despite the transceiver's internal ATU achieving a 1:1 match. This led to experimentation with a coax current balun and further research into G5RV myths, such as SWR claims and the necessity of a balun. The author then describes modifying the antenna to the ZS6BKW configuration, which involves specific changes to the doublet and feedline lengths, and integrating a 1:1 current balun wound on a ferrite toroid. The modifications resulted in improved reception and transmit performance across the bands.

Operating an amateur radio station often involves community engagement, and the Anne Arundel Amateur Radio Club (AARC) exemplifies this with a focus on public service and emergency communications. The club maintains repeaters, provides an Elmer program for new hams, and conducts training and testing sessions, fostering skill development across various age groups and experience levels. Members participate in activities ranging from contesting to kit building, promoting technical proficiency and camaraderie within the local ham radio community. The AARC hosts regular meetings on the first and third Thursday evenings, creating opportunities for fellowship and knowledge exchange. Their commitment extends to programs designed for kids, YLs, OMs, and both new and experienced operators, ensuring a broad appeal. This club's structure supports continuous learning and practical application of amateur radio principles, aligning with the core values of the hobby. Their emphasis on emergency preparedness highlights a critical aspect of amateur radio's public service mission.

A Loop Fed Array Yagi antenna for 50 MHz featuring 11 dBi gain and 23 f/b ratio. In this excellent page the author even includes a detailed drawing in DWG format, with element lenght and spacing measures, in a separa file a full list of material list needed to build this yagi antenna including source and price, the EZnec file for this antenna plan, and a lot of pictures of this LFA Yagi for 50 Mhz. A ten page PDF file containing all infos, is also available to download.

Using our components you can build a rotating tower with greater capability than 3-4 static towers. A rotating tower allows common rotation of HF stacked arrays, VHF and UHF arrays, and antennas mounted at optimum heights. Component design also allows tower shunt loading and end support for wire antennas

A range of easy-to-build RFI filters by John Regnault, G4SWX

RFAC Solutions specializes in providing a range of RF components, including various connector types, cable assemblies, attenuators, and filters. Their product line features common connector standards such as SMA, BNC, TNC, N-Type, MCX, and MMCX, essential for reliable RF signal paths in amateur radio and commercial applications. The company also offers high-power VHF amplifiers, catering to needs for signal boosting in specific frequency ranges. Their offerings extend to dust caps and adapters, which are crucial for maintaining the integrity and versatility of RF systems. The focus on supplying components from South Korea suggests a commitment to specific manufacturing standards and supply chain practices. This resource details a vendor's product scope, useful for hams sourcing specific parts for shack builds or antenna projects. Jeff is listed as a contact for inquiries.

CO2KK exposes some myths about using 75-ohm feedline with 50-ohm rigs and show how to build a cotanget transformer

Italian page about a home made a 1 to 40 balun with pictures and measurements on HF bands.

A field strength meter, a crystal tester and a capacitance meter by Peter Parker VK3YE

A Unique VHF Antenna with gain over a J-Pole Jose I. Calderon, DU1ANV

A project of a 5 Antennas Relay Switch Box, all Switches & Relays have both contacts wired in parallel to improve reliability of operation, to prevent static build up, when an antenna is not in use the feeder coax is grounded.

Ebook by Akira Matsuzawa Tokyo Institute of Technology, Building blocks in RF system and basic performances, Device characteristics in RF application , Low noise amplifier design, Mixer design and Oscillator design

Here we have a ground plane antenna mostly used for 144, 222, 440 Mhz. Its one of the simplest antennas to make. New hams can build this with little to no experience in antenna building.

OZ2OE Technical Home Page - Building a circular polarized yagi

How to build a lightweight amplifier that can be backpacked around.