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GM4JMU shortened dipole for 40 meters band. This article illustrates in detail how to build a resonant antenna for 7.030 MHz. Cut two 10.25-meter pieces of insulated wire, wind 40 turns of wire onto plastic tubing, and connect the wire to a central insulator using a choke balun built of RG174AU coax and a ferrite toroid. Once built, the antenna is adjusted by altering the wire length to produce the lowest Standing Wave Ratio (SWR) for best performance. The guide emphasizes careful building and adjustment for the best results.

Dispels myth about choke balun winding method

Notes on making the W2DU choke balun by placing several ferrite sleeves around a coaxial cable.

A model of a Guanella 1:1 VHF choke balun using a FT140-61 core

RF Choke to prevent hf currents on the feedline. This Magnetic Longwire Balun (MLB) makes it possible to efficiently use a coaxial lead-in cable with all forms of longwires, T-forms or other types of wire antennas, without the need for an antenna tuner.

RF Choke to prevent hf currents on the feedline or...1:1 Choke Balun, sometimes called the "UGLY BALUN"

In this designs G8ODE explains different methods to builds a choke balun

Collection of different techniques to homebrew PVC yagi antennas, including elements assembling, baluns and chokes, radiator box tips and tricks by dk7zb

A homemade VHF/UHF vertical antenna made essentially with RG58 coax cable, with a 9 turns choke balun to prevent the shield acting as a RF Radiator.

Voltage baluns and choke (or current) baluns.

In this article the author describes some new designs of ferrite loaded chokes for suppressing unwanted common mode currents at HF applied to feed lines like choke baluns, but also in the shack, applied to various coaxial, mains and data cables

The main function of the Ugly Balun is to help eliminate rf currents from flowing on the outside of coaxial cable using the principle of choke action.

How to homemade a multi-band HF dipole using 100 meter of speaker wire, 2 strandsm including a homebrew 1:1 choke balun

Communication Coil, Inc. designs and produces custom, high reliability Filter Networks, RF Coils, Chokes, Inductors, Baluns, Toroids and Power Magnetics for communications

MyAntennas.com offers standard and custom made multiband antennas, Baluns, Common Mode chokes and accessories. All products are designed and made by Danny Horvat, E73M an antenna design engineer formerly employed by Cushcraft Corporation.

Homebrew a 1:1 balun consistsing of 4+4 turns of mini coaxial cable over a large ferrite core by m0pzt

Essentially, a choke balun is designed to 'divorce' your antenna from the feed line. if your feed line is coaxial cable then you don't want it to be part of your antenna. you want to be able to deliver all your power to the radiator itself, i.e. 'the antenna'. a choke balun does this admirably

This 6 meter 2 element yagi antenna is simple, compact and effective antenna for 50 Mhz. The design antenna was optimized with AO for best match to 50 ohms, no matching network. A choke balun is recommended to decouple feedline currents.

In this article, author examine stresses placed on common-mode chokes (aka baluns) as hams use/abuse them, examine the efficiency of simple dipole multi- band antennas and their feed systems. Stressing a Balun.

If you ever asked if you need an Unun or a Balun this article is for you. The right question should be do I need a feed line choke or an impedance transformer whose output is configured as balanced or as unbalanced. An impedance transformer can be configured as a voltage transformer or as a current transformer.

Choking balun for lower HF and MF bands. (1.8MHz - 10MHz). Requiring a choking balun to isolate the potential RF pick up on the coax cable as it runs past equipment such as computer within the radio room at lower HF and MF frequencies a simple method of winding RG58 coax onto a Powdered Iron Toroid Core was constructed.

I happened to stumble across some antenna projects showing common mode chokes 1:1 baluns made of some turns of coax wound on T200-2 iron powder toroids.

The mini Radio Solutions miniVNA PRO is the only affordable vector network analyser (VNA) I know of that offers remote wireless operation. This is very interesting because it allows to measure the input impedance of HF antennas installed at height without having to deal with coax cable lengths, baluns nor common mode suppression chokes. However, to render the miniVNA PRO truly field proof, it requires a number of significant modifications.

This article describes the construction of a simple dual-band VHF/UHF end-fed vertical dipole antenna designed for local repeater access using an Icom IC-705 radio. Built from a single piece of RG58U coaxial cable, the antenna consists of a 460mm exposed inner conductor, 450mm of intact coax, and a 9-turn choke balun wound on a 27mm former. Mounted on a 10m Spiderpole, the antenna achieves excellent SWR readings (<1.2:1 on 2m, <1.5:1 on 70cm) and provides effective coverage of local repeaters with unexpected reach into distant locations.

This article clarifies the roles of baluns, ununs, common mode chokes, line isolators, and impedance transformers in amateur radio. A balun decouples balanced antennas from unbalanced feed lines, preventing interference. Ununs serve a similar purpose for asymmetrical antennas. Common mode chokes and line isolators suppress common mode currents, reducing noise. Impedance transformers adjust antenna impedance to match feed lines but do not decouple or suppress common mode currents. Understanding these components is crucial for optimizing antenna performance and minimizing interference.

A C-Pole Antenna for QRPxpeditions describes a DIY C-Pole antenna designed for QRP (low-power) expeditions, inspired by KF2YN’s ground-independent vertical model. After adjustments, it achieved a 1:1 SWR at 14.060 MHz, rising to 2.5:1 at 14.35 MHz. A choke balun, comprising 15 turns of RG8X around a 4” can, was essential for optimal performance. Compact and self-supporting, the antenna enables reliable communication with minimal setup. Contacts included stations across the U.S., and even a 4,600-mile connection to Spain using only 5 watts.

This comprehensive three-part guide examines baluns (balanced-to-unbalanced devices) and their critical role in ham radio antenna systems. The author explains how baluns prevent common-mode currents on feedlines, which can distort radiation patterns and cause unwanted RF in the shack. Various balun types are analyzed, including coiled coax chokes, ferrite-core designs (W2DU), and toroidal-wound versions (Guanella/Ruthroff). Construction techniques for 1:1, 4:1, 6:1, and 9:1 current baluns are provided with practical guidance on wire selection, winding methods, and ferrite core properties. The article emphasizes that proper balun implementation is essential for optimal antenna performance, especially with directional arrays.

DIY project of a QRP Balun. Using a high permeability ferrite rod and an old B&W dipole center insulator, he constructs a choke type balun for QRP use. The balun aims to create as much inductance as possible at HF, offering a high impedance to common mode currents

With increased ES propagation, this lightweight 5-element LFA antenna offers enhanced performance over the Bigwheel antenna's 5dBi gain, delivering approximately 11dBi and forward gain. Designed from G0KSC’s specifications, the 1.8m antenna was adapted for reduced weight using 6mm and 4mm rods instead of heavier tubes. 3D-printed PETG clamps ensure durability and precision, while the first tests showed excellent SWR and element coupling. Though built with a temporary Choke BalUn, the results were promising, with a Pawsey Stub BalUn planned next for further optimization.

For phased C-Poles, matching choke baluns are essential to maintain intended phasing, beam pattern, and gain. The author uses a low-loss, ferrite-core balun design with 19 turns of RG-174/U coax for optimal performance.