18' of coax??

You don't have one of these?
https://www.amazon.com/dp/B000WOHSHM/ref=cm_sw_r_cp_apa_i_p8vHCbNSYV8Z6

 

I'm not doing any soldering while out on the road. I'll bite the bullet and buy what is available

 

You guys and your soldering ... get good quality crimp on connectors and do it right. Quick fixed for an on the road problem.

And before you guys start in in me with crimp on connectors, go learn how to put them on right and which ones to buy.

 

Nope still not working on cables on the road. When I'm driving it's all business. I'll tinker when I get home

 

If for no other reason that “the project” just sits there a long time.

I’ll tell myself, “Okay, tonight. Or, tomorrow”. Ha!

 

270° of 75 ohm cable seems to be ideal for building a phasing harness. I tried 90° once and it seemed impossible to tune. I don't remember the specifics.

 

Funny you post this cause i was just googleing velocity factor and found that same article..

 

I know this is a very old thread, but I feel I need to answer your question. This is because most did not read your question properly.
There is a big mix up here because of a coincidence. Forget about this 18ft of coax thing. That is, 18ft of 50ohm coax, is for another topic. You need to feed those antennas with 75ohm coax, 3/4 of a wavelength taking in the the velocity factor, to be exact. This is for impedance transformation. You see, when you calculate this for 27.055, Ch8, it happens to be almost precisely 18ft. It's out by just 1.4mm. This is where the confusion stems from, and most people who replied have no idea about this. And like I said, did not even pay the courtesy to read your question properly, they're too busy perpetuating CB myths. Here's the maths to back up what I am saying... in metric, I'm Australian. You can easily convert it to feet online.

299.79248 divided by the frequency 27.055
=11.081m
11.081/4= 2.77m
2.77x0.66= 1.828m
1.828x3= 5.485m or 5485mm
This your length of RG59 coax either side which converts to 17.995 ft.
Incredible huh?

Jeremy.

 

18 feet of coax and which type coax.
.
Some of you people are really funny because of all the things that you think that you know that are just plain incorrect. For example : all this 18 feet of coax nonsense.
. First, 18 feet of coax is the half wave length of the CB frequency ONLY, I repeat ONLY, when it is traveling through air. Therefore the half wave length is not 18 feet when it is traveling through coax. So all you wizards of smart have been wrong all along. Does your CB radio setup work at all without coax connecting the radio to the antenna? Bleep no. Coax is a necessity to connect the radio to the antenna. And, the half wave length of CB frequency traveling through coax is..... 11 feet 10 inches. And guess what? Even that length has zip, zero, nada and not a blessed thing to do with how long your coax should be.
. Second thing is this whole question about which coax is the proper type for your CB radio installation. I try to keep it simple and bypass all the multiplex garbage in newer trucks and just run a short length of 50 ohm coax from the radio to the single antenna. Any 50 ohm coax will do just fine. Learn this - all coax has low over its length. Shorter lengths have less loss than longer lengths of the same exact type. When they measured the results for coax they used 100 feet lengths of coax. So for RG 8, they applied a signal to one end to the coax and at the end of the 100 foot length they measured the output at 78%. Therefore: 100% - 78% = 22% loss per 100 feet. 22% loss per 100 feet of RG 8 = 0.22% loss per foot of RG 8 coax. 0.22% loss per foot of RG 8 coax x 18 foot length = 3.96% loss per 18 feet of RG 8 coax. 0.22% loss per foot of RG 8 coax x 9 feet of coax has 1.98% loss. And for the record - RG 58 has 0.34%loss per foot of coax. Which means 0.34% loss per foot 0f RG 58 x 9 feet of coax = 3.06% loss per 9 feet of RG 58. Learn to do the arithmetic.

 

The length battle will go on as long as there is noise toys so your beating a dead dog there sir..
What coax,thats another issue to..Some are built differently as im sure you know so yes rg 8 x vs times micro wave or even other brands can make a difference in your set up..Some like me get a lil anal about losses and want to tighten up those # in various ways...

Yes i agree that to many follow blindly re cb stuff...As many times i mentioned to newer users about the ground wire(Ground wire from mount to chassie)being incorrect its still around and folks are still doin it..
Anyways bub,keep on showin what you know so that it helps others who need to know..