11m / CB Radio: How Long Should My Coax Be?

Is it true that coax needs to be 18 feet - or multiples of 18 feet for your CB Radio? I'm going to address the myth about specific lengths of coax that some CB operators believe will magically match their antenna to their radio. We'll explain why the impedance along the coax varies with frequency and length, and how a mismatch can cause losses and affect the SWR of your system. We'll also give practical advice on how to properly match your antenna to your radio and minimize losses.

Callum.

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[poormanstube]

From an American trucker, I'd like to say thank you for the simplified ways to get my swr figured out . I will be watching out for any updates from your channel.

[saxmusicmail]

Just this past weekend I went through all of this, exactly, but all calculations made in feet (468 / freq in mhz) with my grandson. I have the Rig Expert AA-54, which graphs. We built a dipole, deliberately made the wire a few inches longer than calculated. The dip was offset just as you showed. We recalculated from there, cut 1.5" from each side, centered the dip right around Ch. 20. SWR was 1.5 on Ch. 1, 1.2 on Ch. 20, and 1.4 on Ch. 40. But he got to see all this first hand. A great lesson! He could not transmit... he had his Dad's CB, but could not find the microphone.

[_PikeWxRadio]

I wish you made this 16 years ago hahah. I acquired my first cb radio and was so misled and fear-mongered about SWR and blowing up my radio that i barely used the thing. I was not in amateur radio at the time and youtube wasnt all that flooded with trustworthy information at the time. I cant tell how many forums and articles i read that touched on this topic and i was still lost. Thanks for removing the mystery of radio and providing accurate information!

[warrenpercell]

When I was into CB here in the US back in the 90's, I was told coax had to be cut in 3 foot intervals due to SWR. I didn't know any better, so when I bought my base antenna coax, it was 51 feet long. Fast forward to 2020 when I got my ham license, I'm thinking back to this coax and the 3 foot interval and it doesn't make sense, and I can't believe the malarkey that people I trusted spewed. Thanks, Cal. All the best. Cheers. KO4QOA

[SHAMAN.VISION]

Satisfying to watch., You're a master.

In 10 minutes painted a picture that taken me years to wrap my head around..

[simonappleby]

So in 2018 my wife passed me down from the loft my ham international CB radio from the 1970s and I switched it on and it bloomin well worked! Put a vertical up and there was two people on in our area. All I was interested in was DX so I went on SSB and got a few contacts into Italy. A really nice lady used to come and chat with us local guys and she went on about how I should get my licence. . . So I did. I was watching your channel as well and thought that it was a natural progression. What a difference. . . I am so pleased with the hobby and the fun that I am having. I don't know why CB is a touchy subject on the ham radio as it was the first form of social media for us before the internet.
I was actually taken to the crew room of our life boat station when I casually mentioned that I was interested in taking the exam and the guy who I was introduced to nearly collapsed when I told him that I was going on 11meters SSB. . . . He said that I would have to go to the local club for 3 years before being put through the course, so I did it with Essex ham. Ha Ha. Keep the videos coming.
Kind regards Simon.

[VENMW]

You’ve cleared up a few things on antennas, SWR and coax length! Thank you from VE3NMW.

[richarde]

I can’t even begin to imagine what was wrong with my setup in the 70’s. it wasn’t grounded, the coax (RG8) was cut to length from the 60’ high wilson shooting star (4v 4h elements) antenna to the radio in the basement. the antenna was simply adjusted to the measurements in the instructions. i did have an archer swr meter but that’s nothing like having a rigexpert analyzer. I do remember getting shocked all the time if my hand was on the mic and I brushed up against the amp. I was just thrilled that my parents even allowed this monstrosity to be attached to the side of the house.

[GroundControl]

My favorite YT channel. Cal, you are the man! Waving from my tech bench. 73👋🏻

[windseeker]

New to CB radio. Installed one in my vehicle and then a base in the home.
This helped me understand SWR and answered a lot of questions I didn’t know to ask.

[timprice]

Great video. In my younger days, on CB, everyone said you have to use 11 feet of coax on a 102 inch whip mobile antenna for everything to work right. Over a short period of time I figured out that was baloney! Thank you Cal! 73s ND4A

[Aswaguespack]

There’s so many funny “rules and guidelines” when it comes to swr, feedlines and power. But one thing is definitely true and that’s if you let the smoke out, something stops working. It’s all about the smoke. 😂😂😂 KZ5Y

[leighstevens]

Thank you for explaining it in simple terms

[jaym]

Your videos are not only informative but entertaining as well. Sometimes I get lost for hours watching them and when I do I always learn things. Thanks for doing what you do.

[aquariumsmaintainedbyandy]

Fantastic information and fantastic video

[TheArtofEngineering]

It is NOT the length of your coax that matters….. it is how you use it! 😂

[alanslade]

Wow been on and off CB for 45 years, and all I've ever heard is it's all about the length.of your coax, and it's never been a problem with me anyway.but just at the end of your video you said, if I got some extra wire I would coil it up anyway . which has only just clicked that you coil up the ARIEL, bottom, middle or its on the top, so the moral of the story is it don't matter.thank you very much . DX COMMANDER.ALAN IN LUTON 💯👍

[ChrisDitchDigger]

Keep providing great antennas and great information. You are and invaluable service to the whole radio community (cb included) thanks Callum

[alangoulding]

Like yourself Callum I never could understand why operators wanted the one to one swr like it made all the difference...well explained and 100% correct....Top mam 73s Callum

[rolandweaver]

Hahaha….I remember something about this argument for more than 40 years!!! Laughed then, and still laughing about it. As an RF expert (now retired), it simply and easily ID’s those that don’t have a fundamental understanding of…. Well, I don’t want to pour any salt on wounds, but you did a very nice job of letting the air out of a few balloons. And yes, I had 10 or 12 extra feet of RG-8 coiled up on the floor by the window where it went outside to the antenna. One friend just couldn’t stand that. Hahahaha. Good job!!! …as usual…