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2-Element parasitic Yagis for the Shortwave-Bands 10-12-15-17-20-30m. The antennas are feeded with the DK7ZB-match. A quarter-wave choke of coax is grounded at the socket.

Here is a sure fire way to make end-fed halfwave antennas fed with a 50 ohm coupler work - without long radials, grounds, chokes, voodoo.

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.

Excellent article on limiting noise using chockes by Chuck Counselman, W1HIS

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

Rolling your own transformers and chokes. Rewinding salvaged power transformers, considerations and step-by-step guide

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

BIRD RF power measuring, new and used, HENRY RF power amplifiers (used HF amps), TOHTSU coaxial relays, SAMLEX power supplies, RFI chokes reduce interference, Parts parts, tubes, Used amplifiers, radios, antennas and accessories, Los Angeles, CA.

Based on original G2BCX design this J-Pole antenna for the six meter band is made with a homemade ribbon cable. The antenna shown in this article includes a coaxial cable choke feed to remove RF currents from flowing on the outer of the cable.

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.

DF9CY implementation of W1HIS suggestion of inserting a common mode choke into a 40m antennas feed-line.

In this article K3DAV show a very simple way to make an RF choke coil that will remove your RF feedback troubles

The intrepid newcomer encounters common mode problems in a mobile environment. Implementing some common mode chokes will be possible to reduce interferences

Understanding Common Mode and Differential Mode Currents on Transmission Lines by K9YC

Voltage baluns and choke (or current) baluns.

A trap on the coaxial cable, also known as choke, helps to eliminate the sneaking of the reflected RF- energy to the shack. The trap can be made from the coaxial cable that feeds the antenna

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

A chart presenting the results of impedance measurements made on a variety of common-mode choke implementations across the frequency range 1MHz to 30MHz by G3TXQ

How to make an effective RF Choke. The coiled coax choke is the easiest to make but also the least effective. This article includes some general guidelines for winding coax chokes on a 10cm PVC pipe using RG-58 or RG-213 coax cable.

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

A general article on CMC, common mode choke include a description and tipical usage.

May 2015 Radcom Article on common-mode chokes that can be used for control cables, phone lines, but mostly on typical HF antenna systems. This article explain what common mode chokes does, why you meay need one, properties common mode chokes should have, how to build and measure performances.

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

Chart that present results of impedance measurements made on a variety of common-mode choke implementations across the frequency range 1MHz to 30MHz by G3TXQ

Manufacturer of transformers, inductors coils and chokes. Custom winding, EMI / RFI Filters, Antenna Windings on ferrite rod, Antenna Winding on phenolic. Any antenna coil designs.

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.

Using Chokes and Traps: how to make them, how they work.

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.

Manufacture capacitors, sensors, diodes, varistors, chokes, inductors, ferrites and accessories

If you want to build your own common mode choke, this article explains how to measure the efficiecy of your choke before using it. In the examples has been used Amidon FT240-31 toroids.

How many times have you heard the advice to coil a few turns of coax at the antenna end to form a choke. How to find out if your common mode current choke really works

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.

Finding the the best ferrite material for a common-mode choke. How to create efficient ferrite cores and how to measure them

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.

Home brewing a high performance, high power common mode choke for HF bands

This is a small collection of K9YC info and my experiences. Problems by feed lines of 1/2 lambda length. CMCs in transmitting and receiving systems. Antenna unbalance, Maximal allowed power, Choke winding tips.

Common-mode chokes are useful solutions for RFI reduction. Winding a few turns of coaxial cable on the FT 240-31 toroid can reduced the noise below the received noise floor. In this article author measure different chokes

This article is an attempt to shed some light on this misunderstood component, covering topics like why you need a common mode coke, what it does, what properties it should have, ho to build one and how to measure its performance.

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 is a power amplifier project for a RF 600W 1.8 MHz to 70 MHz linear amplifier including a Low Pass Filter. Projects includes schematics, pictures, PCD design, fans details, note on PA ferrite chokes and assembling instructions