CB Dipole antenna

[nicky]

I have read about dipole antennas for 11 meter and I want to put up a horizontal dipole and someone posted about a 1/4 wave being the best for DX. I don't understand the difference between 1/4 and 1/2 wave as far as the length of the wire or tubing used . Could someone shed some light on this? Thanks much

 

[BJ radionut]

Half wave overall total

Amateur Dipole Antenna Calculator

This calculator is designed to give the horizontal length of a particular dipole (including Tees) antenna

www.csgnetwork.com

Diople Calculate

www.cdxa.org

 

[BJ radionut]

DIPOLE AND INVERTED V VEE DESIGN AND CALCULATOR

hamuniverse.com

 

[sp5it]

Balun is not optional, it's mandatory.

 

[nicky]

Balun is not optional, it's mandatory.

How do I make a balun? Just coil the coax?

 

[whiteastro]

Here is one I just bought ready made. MFJ-918
You can buy them ( Dipole ) ready made on ebay really cheap.

 

[sp5it]

Yes. 5 turns of coax does the trick.
See attached image. You aim for green area.

 

[Riverman]

https://www.worldwidedx.com/threads/1-2-wave-inverted-v-dipole-antenna.264807/

https://www.worldwidedx.com/threads/dipole-antenna.249881/

https://www.worldwidedx.com/threads/question-about-making-a-dipole-antenna.90198/

https://www.worldwidedx.com/threads/homemade-dipole-antenna-help.88033/

Lots of threads exist. Just search forums for CB Dipole Antenna.

 

[Shadetree Mechanic]

I have a wire dipole strung up with clothes line between two poles on the corners of my garage. Only about 20 feet up, it works great for DX. I also have a starduster on the same garage, I am going to put them on an antenna switch so I can easily compare the two.

 

[Eldorado828]

I have a wire dipole strung up with clothes line between two poles on the corners of my garage. Only about 20 feet up, it works great for DX. I also have a starduster on the same garage, I am going to put them on an antenna switch so I can easily compare the two.

Balun or no Balun? I just built one with no Balun and wondering how it will do.

 

[sp5it]

Dipole feed with coax always need a 1:1 balun. Otherwise coax will radiate, will be also taking it's part on RX picking up local noise.

 

[Shadetree Mechanic]

Balun or no Balun? I just built one with no Balun and wondering how it will do.

I did mine without because at the time, I didn't know that it needed one.

 

[fourstringburn]

Balun is not optional, it's mandatory.

Dipole feed with coax always need a 1:1 balun. Otherwise coax will radiate, will be also taking it's part on RX picking up local noise.

100% on this!







Take note, you're feeding a balanced antenna with an unbalanced feedline such as coax and will cause the unequal current to flow back on the coax line…hence the term "common mode current".

A 1:1 choke balun is used to control this by adding enough choking impedance to a given frequency or broadbanded to cover a much wider range.

"Ugly" air wound chokes work and are simple to make. Better ones are small coax or teflon wire wrapped around a 2 x 1/4" mix 33 (or 43 if higher bands are used more) ferrite ring or in series with 2 rings and installed in a weather proof box. Typically 2 gang electrical boxes are used with RF connections for easy install.

Think of it this way by definition, Bal-un, balanced to unbalanced.

 

[whiteastro]

I have a wire dipole strung up with clothes line between two poles on the corners of my garage. Only about 20 feet up, it works great for DX. I also have a starduster on the same garage, I am going to put them on an antenna switch so I can easily compare the two.

I have one up in my attic and it amazed me one time with the clean quite DX I got out of it. It's hooked up to my Dosy meter with a switch that my StarDuster is on also. I'd like to get my Dipole outside also but my climbing days are slowly drawing to a close.

 

[Shadetree Mechanic]

Now that I am thinking about it, putting a longer coax on my dipole so I can coil a balun is a good excuse to check out the flat garage roof before the cold weather hits.