Building an Air Choke or "Ugly Balun"

In this video, I build an Air Choke, or "Ugly Balun" for my Ham Radio antenna.

[@toftie177]

Great demo and I love the admission of your error. Easily done and I'm sure we have all done similar things in the past. Great job. :-)

[@davep6977]

Good video. Minor twist. When at the box store getting the 4" PVC. Look for 4" drain pipe. Same as above but it has 3/4 holes every 6" and a PL-259 just fits nicely thru them leaving the tails in the center

[@jfrphoto01]

The ugly balun is a misnomer. It should be called what it is, a common mode choke coil or a line isolator as it does no impedance transformation. A balun transforms a high impedance load to the characteristic impedance of your coax ( 200 ohm to 50 ohm or 4:w). That being said, this is an excellent video on how to build one! Cutting the coax is something anyone who has been doing this type of hobby will end up doing! I have been in the radio hobby since 1967 and have done my share of "oopsies"! Like the perfect install of a PL-259 only to forget the coupling ring or the reducer on a smaller coax when you are done soldering!

[@hollyb1]

When you cut through the end of the cable that was totally worth a like, way to roll with it man.

[@PatrickRobinsonZA]

Legend! Love the cut!! had a good chuckle !! My kind of fun!

[@roguetrooper70]

Hell it's never a mistake... you just made a new mod and brought it into the wireless age.. "The Wireless Choke"

[@radiofanuk]

I built one. Thanks for the inspiration, I’d have just bought one 😅

[@dovergerald1579]

Man sounds like something I'd do. Haha! Thanks for making this video!

[@GrossMaster2000]

Thank you Jim.

[@fuguf1sh]

Glad I'm not the only one who does stuff like that lol. '73.

[@K1ZEK]

I had to laugh out loud at the cutting of the cable in the pipe, it sounds like something that could be easily done by any Ham. HI HI or do I have to say lol. O well great video and project. 73 cul k1zek...Leo

[@incaroads001]

You didn't have to admit that. Yer a brave man.

[@massoud999]

I am using the metric system and 20 feet should be about 6 meter, but looking at what you show on the video it looks much shorter. How long should the coax be in centimeters/meters? Thanks for the video.

[@billbates7810]

Hi, I like your video, straight in & straight to the point, no preamble or waffle! Could you tell me what inductance the coil was and what band was it for? I’m looking to build one from RG58 for 160 m band. God bless, Bill G6ATO

[@lundebc]

How did you calculate the number of coils?

[@ea6wu]

Thanks for the video!

[@romeosisonjr4262]

very helpful!....will start to make one of this with my own choice of PVC! cheers! - K-H-0-R-A

[@Nobody-ld7mk]

Back in the 70's Hy-Gain engineers used choking common mode reflection with basically with the same method, they added three additional turns atop the final three of the RF Choke. Magnetism has a polar directional field so I've tried three additional turns atop in the opposite direction with success. "See PG. 10 of the manual. www.cbtricks.com/ant_manuals/hygain/model_416/graphics/hy-gain_416_eliminator.pdf

[@James_Bowie]

One of those d'oh moments we've all had.

[@Sky1]

This might sound dumb but why not use a section of coax that is 20' longer so you can simply wrap it just before you connect it to the antenna? That's what us old CB'rs use to do but, hey what do they know.

[@stevewithnell911]

Air wound chokes are single band devices, so work well for CB (single frequency band) but not great for the ham bands (many different frequency bands)...when you roll up a length of coax as you describe, well you just made an air choke and provided the length and diameter of coax you roll up is right for 27MHz, it will work very well for you... A good choke for 80-10 metres is a lot more complicated than shown in the video, uses ferrite (usually lots of...). There is more smoke and mirrors around baluns than anything else and some are just snake oil.

[@t.n.6978]

Odlicno !! Hvala !!

[@TeamYankee2]

What does the diameter of the pipe represent ?

[@BackBeeBrokenBeekeeping]

All coax has a minimum turn radius. So the width of the pvc needs to be greater than 2x the radius of your allowable coax bend.

[@WX4CB]

ok so question.... i just did the same thing and was told 17 turns of rg8x.... I did that and it completely screwed up the 40m band. how many turns did you end up and how do you test it (put a dummy load on one end and put an analyser on the other and it was 1.2:1 1.8-50mhz)

[@christianpaul3303]

"Should be around 20 feet" - for what band? All HF bands?

[@83redgrass]

Wondering too.

[@mohamadibrahim1601]

would a choke prevent a coax from radiating??

[@stevewithnell911]

The purpose of an RF choke in this context is to stop RF current flowing on the outer skin of the coax. This is what causes the coax to radiate. There is a secondary problem. If there is common mode current on the coax outer, then the coax will be prone to having RF current induced from noise sources, which increases the noise on receive too. An air cored choke like this one, tends to be good at one frequency and can make things worse at others. To make a really good broadband choke, you need a good chunk of ferrite.

[@tjalessi]

Stupid Question but if you are building one for 160m-10m how many feet? I built the same one and put about 25 feet of coax around for good measure. But what is the correct # of feet for 160m, does anyone know?

[@DickieBird888]

26 turns around a 4 inch pipe.... detailed info here.. www.karinya.net/g3txq/chokes/

[@paulhastings3109]

Why do you use rg 58

[@johnsmiley2922]

Why such small coax? Why not the same coax as the feedline?

[@Appalachiangirl]

which is better for CB a Ugly Balon or antenna tuner ? trying to figure out what I need to run a mountain line antron 99 to talk ham and Cb. Any help would really be appreciated. I was told by someone that a antenna tuner does the same thing ?

[@sclerismockrey8506]

They told ya wrong, sorry. :) They are two entirely different things accomplishing two different goals and you probably don't need either one for your CB. A tuner aids in matching the impedance of an antenna system (the wire antenna and any coax or other feedline) to the (usually standard) 50 ohm impedance your radio wants to see at its antenna port. It is required if you are using antennas that have varying impedance needing to work across a wide range of frequencies. Your Antron 99 is designed only for 26 to 30 MHz (CB and the ham '10 meter' band) and you don't need a tuner with it if it's set up correctly. A choke/'balun' like this does not tune anything, but it reduces common mode current from flowing on the outside of the coax cable, and is not necessarily required unless you are having problems with stray rf coming back down the coax and into your gear (which again should not be an issue if your Antron 99 and CB radio are correctly set up).

[@LoneStar_1836]

I thought it was a cool shot with the saw.

[@kkandretti]

Can this be hung from the ceiling in the Radio room or does it have to be outside near the antenna... ?? Thanks

[@JimHaslett]

The closer to the antenna, the better. You really want it outside at least.

[@kkandretti]

Thanks ..:)

[@tim90defender]

Hung vertically or horizontally,I heard it makes a difference .

[@generoll4027]

ok, so what does that accomplish?

[@JimHaslett]

The 1:1 choke "balun" is not actually a balun. It's function is to help eliminate rf currents from flowing on the outside of coaxial cable using the principle of choke action. Another "name" for it is the air choke.

[@moeshickenyay]

Jim Haslett ok, so what does this accomplish?

[@sclerismockrey8506]

@@moeshickenyay Really? He just told you -- "... to help eliminate rf currents from flowing on the outside of coaxial cable...". For further education, do your own homework and research why that matters and how keeping rf common mode current off your coax helps keep noise and stray rf out of your gear. If you're already watching a video about common mode chokes/baluns, you must know at least enough about such things that it should have been fairly intuitive, if not obvious.

[@jacobcastro1885]

@@sclerismockrey8506 we know what it is supposed to do. The question is what does it actually do? Does this arrangement provide enough resisting impedance to prevent RF flowing to the outside of the coax on a particular range of frequencies?

[@mattikankaanpera8535]

Oops 🤭

[@Swoop180]

Oops!

[@dixiedog1179]

New connection not very expensive....

[@wesyjam]

😂

[@nn6aa]

that's not a balun...

[@sclerismockrey8506]

amen