- Noise Reduction on 40m
- DF9CY implementation of W1HIS suggestion of inserting a common mode choke into a 40m antennas feed-line.
[ Hits: 1379 | Votes: 0 | Rating: 0 ]
- A High Performance RF Choke for the HF bands
- Home brewing a high performance, high power common mode choke for HF bands
[ Hits: 139 | Votes: 0 | Rating: 0 ]
- A model of the W2DU 1:1 choke balun
- Notes on making the W2DU choke balun by placing several ferrite sleeves around a coaxial cable.
[ Hits: 9668 | Votes: 7 | Rating: 2.29 ]
- About Common Mode Choke
- A general article on CMC, common mode choke include a description and tipical usage.
[ Hits: 886 | Votes: 0 | Rating: 0 ]
- Build your own RF-Choke
- 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.
[ Hits: 730 | Votes: 10 | Rating: 8 ]
- Chocking the End-Fed Antenna
- Stop common-mode current when transmitting with an end-fed antenna. Unbalanced antennas are very prone to currents on the outside of the coax.
[ Hits: 822 | Votes: 1 | Rating: 8 ]
- Choke balun
- 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
[ Hits: 572 | Votes: 11 | Rating: 7.27 ]
- Choke Balun Designs
- In this designs G8ODE explains different methods to builds a choke balun
[ Hits: 2882 | Votes: 6 | Rating: 5.5 ]
- Chokes and Temperature changes
- The influence of temperature changes in Common Mode Chokes. To get an indication of the impedance behavior when the core temperature changes, the author tested a CMC by heating it with a hairdryer, and measuring its temperature with an infrared thermometer. When the CMC temperature rises from 30C to 90C, the frequency of maximal impedance shifts down from ca.10 MHz to ca.7.2 MHz, or by a factor 1.4.
[ Hits: 43 | Votes: 0 | Rating: 0 ]
- Common mode chokes
- Excellent article on limiting noise using chockes by Chuck Counselman, W1HIS
[ Hits: 5244 | Votes: 12 | Rating: 5.17 ]
- Common-mode chokes
- 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
[ Hits: 598 | Votes: 2 | Rating: 4 ]
- Do not wind chokes on red toroids!
- 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.
[ Hits: 182 | Votes: 0 | Rating: 0 ]
- Feeder Radiation
- Connecting centre fed antennas, dipoles, yagis, rhombics, loops to coaxial cable, unless care is taken, it is not difficult to end up with feeder radiation resulting in power loss and the radiation characteristics changes
[ Hits: 1826 | Votes: 4 | Rating: 8 ]
- High Performance common-mode chokes
- 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.
[ Hits: 641 | Votes: 1 | Rating: 10 ]
- High Performance Common-Mode 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.
[ Hits: 124 | Votes: 0 | Rating: 0 ]
- Homebrew RF chocke - Magnetic Longwire Balun
- 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.
[ Hits: 3402 | Votes: 3 | Rating: 10 ]
- How Common Mode Chokes Work
- Examine the function and operation of a common mode choke and the way it reduces unwanted interference. Common Mode Choke vs. Single Choke
[ Hits: 736 | Votes: 2 | Rating: 10 ]
- How to evaluate Choke performance
- 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.
[ Hits: 206 | Votes: 1 | Rating: 8 ]
- How to find out if your choke works
- 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
[ Hits: 207 | Votes: 1 | Rating: 9 ]
- Isolation chokes for 160m verticals
- An article on how much impedance you really need and how small can be a chooke for top band vertical antennas by N6LF
[ Hits: 617 | Votes: 0 | Rating: 0 ]
- Patented RF choke test
- A reproduction test of a a binocular ferrite core and winds a total of 7 turns is a patented rf choke with an unusual winding, although this winding scheme reduces the inductance, it might result in a much larger bandwidth over which the choke has a sufficiently large impedance. The Author test this model by reproducing the choke.
[ Hits: 102 | Votes: 0 | Rating: 0 ]
- RF choke or 1:1 balun
- RF Choke to prevent hf currents on the feedline
or...1:1 Choke Balun, sometimes called the "UGLY BALUN"
[ Hits: 3233 | Votes: 5 | Rating: 2.6 ]
- RF Choke with Bifilar Windings
- This article presents an RF Choke featuring an 11-bifilar turn winding of #14 house wire on a Fair-rite FT240-31 toroid. The choke is enclosed in a 3D-printed case from Thingiverse, though this may pose thermal concerns at higher power levels. With SWR concerns up to 30MHz, the author plans to employ two series chokes at the rig input for improved performance. This choke offers versatility for portable use, with potential mismatch resolution using an antenna tuner. Further testing is anticipated upon the arrival of new cables.
[ Hits: 46 | Votes: 0 | Rating: 0 ]
- RF Chokes
- 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
[ Hits: 887 | Votes: 2 | Rating: 7.5 ]
- Some secrets of Common Mode Chokes revealed
- 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.
[ Hits: 171 | Votes: 1 | Rating: 10 ]
- Trap on Coax Cable
- 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
[ Hits: 937 | Votes: 2 | Rating: 6.5 ]
- Wind your own RF Choke
- Learn How - Winding your own RF Choke, Inductor Winding instructions
[ Hits: 1345 | Votes: 4 | Rating: 8.75 ]
- Winding style of toroid chokes and baluns
- Dispels myth about choke balun winding method
[ Hits: 9794 | Votes: 14 | Rating: 6.78 ]