CB antenna coax length

[LandCruiserPhil]

I need to make a custom coax for my CB antenna, does the length given a choice make a difference in performance or ability to tune SWR's in? It will mount to the front bumper and my minimum length could be as short as <10ft. Also the antenna if it makes a difference is a 3' Firestick on a spring.

 

[george_tlc]

Length of coax won't matter since CB sucks at best

cheers,
george.

 

[1911]

No; use just enough coax to go from the radio to the antenna.

 

[ntsqd]

There is a lot of lore about what minimum length a CB coax should be. I've never found any of it to matter.

 

[1911]

There is a lot of lore about what minimum length a CB coax should be. I've never found any of it to matter.

"lore" is a very polite way to put it!

 

[rusty_tlc]

"lore" is a very polite way to put it!

 

[Kofoed]

No; use just enough coax to go from the radio to the antenna.

....then check swr

 

[alia176]

We gotta bring Copper State out of the dark ages....

 

[rusty_tlc]

We gotta bring Copper State out of the dark ages....

Just get one more guy on 2M then tell everybody on CB you guys are talking $hit about them on the trail. Even if it's not true a couple of guys will get 2M rigs just because they cannot have stuff going on they don't know about. Once three or four guys are using 2M and have reliable comms that cover more than a few miles everybody else will come around.

 

[LandCruiserPhil]

Just get one more guy on 2M then tell everybody on CB you guys are talking $hit about them on the trail. Even if it's not true a couple of guys will get 2M rigs just because they cannot have stuff going on they don't know about. Once three or four guys are using 2M and have reliable comms that cover more than a few miles everybody else will come around.

Yep many of us are running both

 

[Behemoth60]

does the length given a choice make a difference in performance or ability to tune SWR's in?

Yes. The formula is simple. Longer transmission = poorer performance. No impact to swr.

Antenna length, antena position and ground plane is critical to performance and swr. The wire that it connects to, however, is inconsequential compared to those other factors.

 

[alia176]

Slight hijack

Phil,

I was curious, did your club standardize on a particular brand of HAM radios? We're all running Yaesu variants, with the exception of one fella.

 

[LandCruiserPhil]

Slight hijack

Phil,

I was curious, did your club standardize on a particular brand of HAM radios? We're all running Yaesu variants, with the exception of one fella.

No really across the board in terms of brand. Still a new but growing concept for the club. Myself and a few other have gone with Kenwood 281-A due the ability to fit in the DIN and have the AARP approved front speaker.

I would be interested in seeing your installs to help others with ideas.

 

[alia176]

That's pretty slick dude, nice job!

Here's a link to my remote head install: https://forum.ih8mud.com/electronic-toys/452831-yaesu-ft-8800-remote-head-install-twist.html

The main head unit, slightly larger than your Uniden CB sits under the driver seat on the carpet.

Email (not PM) me if you have any specific questions.

 

[rusty_tlc]

Yes. The formula is simple. Longer transmission = poorer performance. No impact to swr.

Antenna length, antena position and ground plane is critical to performance and swr. The wire that it connects to, however, is inconsequential compared to those other factors.

For the lengths used in automotive applications line length is not a consideration. The type of coaxial wire used will have a much greater impact.

 

[jonheld]

Myself and a few other have gone with Kenwood 281-A due the ability to fit in the DIN and have the AARP approved front speaker.

You're welcome.

 

[OregonLC]

CB shop guy had me keep my lead to 18ft and not cut it. Folk lore or valid practice?

 

[alia176]

CB shop guy had me keep my lead to 18ft and not cut it. Folk lore or valid practice?

Yeah, my local CB shop said the same thing too!

 

[Cruiserdrew]

I don't know where that CB 18 foot thing got started. Likely some fraction of wave length, but inconsequential. CB blows, I can't believe any intelligent 4 wheelers still use it.

I've run that same Kenwood 281 for the last 6 months, and it's a nice radio. The only thing I don't like is the low power setting-it doesn't go lower than 20. Otherwise, great radio with a superior microphone.

 

[rusty_tlc]

18' is roughly 1/2 of a wave length for the CB band, which means absolutely nothing when we are talking about the wire that connects the radio to the antenna. Most likely what happened is that some body that half way understood antenna theory had problems with his POS CB and tried using a new 18' coax wire to hook up the antenna, suddenly his radio worked way better than ever. In true pseudo science manner they attributed the result to the wire length when it was probably just a crappy connection in the old wire that cause the problem all along.