What’s the deal with coiling CB and GMRS antenna wire?

MountaineerTom

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I’ve read it’s ok to do it also that you shouldn’t.

So which is it? And why?
 
Its complete, and utter bullshit. There are situations where it will *appear* to improve things while actually masking real problems - due to technical issues that I really don't understand that well - but I trust those who know a lot more about RF than I do. Run as short a coax as you can/need to - the old "multiples of 9 feet, 3 feet, 6 feet or whatever" for CB is an old wives tale.
 
17' is approximately 1/2 a wave length at the 27mhz freq. and how this works can take more time to explain than I have here. I've used less lengths of 9-12' and had no significant differnces at this low power. Also if you cannot snake the excess coax I would not make coil less than 12" in diameter.
 
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If you are truly interested you can watch and make your own decision.
I always tune my coax separately into a dummy load for the middle of the target range of frequencies.

standing waves impedance matching & wave tuning

It is nearly 30 min long but if you are into radio or audio it should be insightful.

Oh and to answer the original question if using a quality coax then coiling or just "stuffing" shouldn't make any difference.
 
Its complete, and utter bullshit. There are situations where it will *appear* to improve things while actually masking real problems - due to technical issues that I really don't understand that well - but I trust those who know a lot more about RF than I do. Run as short a coax as you can/need to - the old "multiples of 9 feet, 3 feet, 6 feet or whatever" for CB is an old wives tale.

Meaning, it‘s ok to coil the excess up?

For example, I don't remember what length antenna wire I used, but it was well more than enough. I ran it from a mount above the rear view mirror, under the drivers side roll bar padding, down to the tub where the OEM wiring harness runs, through the grommet at the end of the tub then out under the tail light and to the antenna. All the excess is coiled up and hanging in the fender/behind the tail light. I don’t recall how many coils or the diameter but if I had to guess it was 2 to 4 coils and 10-12” diameter. My SWR was right at 1.5 on channel 1 and just barely higher on 40 last night when I swapped my 2 foot firestik for a 3 foot firestik that I had. I figured close enough and left it alone.
 
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Meaning


Meaning, it‘s ok to cool the excess up?

For example, I don't remember what length antenna wire I used, but it was well more than enough. I ran it from a mount above the rear view mirror, under the drivers side roll bar padding, down to the tub where the OEM wiring harness runs, through the grommet at the end of the tub then out under the tail light and to the antenna. All the excess is coiled up and hanging in the fender/behind the tail light. I don’t recall how many coils or the diameter but if I had to guess it was 2 to 4 coils and 10-12” diameter. My SWR was right at 1.5 on channel 1 and just barley higher on 40 last night when I swapped my 2 foot firestik for a 3 foot firestik that I had. I figured close enough and left it alone.
The best thing to do is to cut the excess off and re-terminate.
 
Meaning


Meaning, it‘s ok to cool the excess up?

For example, I don't remember what length antenna wire I used, but it was well more than enough. I ran it from a mount above the rear view mirror, under the drivers side roll bar padding, down to the tub where the OEM wiring harness runs, through the grommet at the end of the tub then out under the tail light and to the antenna. All the excess is coiled up and hanging in the fender/behind the tail light. I don’t recall how many coils or the diameter but if I had to guess it was 2 to 4 coils and 10-12” diameter. My SWR was right at 1.5 on channel 1 and just barley higher on 40 last night when I swapped my 2 foot firestik for a 3 foot firestik that I had. I figured close enough and left it alone.
Ive heard that big circles/coils wont really mess with the SWR, but its when you start making tight bends and kinks in the cable is when you have issues- I try not to have any coils, bends, loops, kinks whatsoever.
 
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My old CB setup was a Uniden Pro 510xl, 3' firestik with spring, and 18ft cable. I had to run the cable everywhere to not get any coils or kinks in it, so it could be as straight of a line as possible. I could never get my SWR below 3.5ish. My new setup (waiting on 1 last piece) is the Uniden Pro 520xl, 10ft cable, and 2' firestik with no spring. My old cable was frayed at the CB end, so im hoping a brand new, and shorter cable will fix my SWR
 
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tenor.gif
 
Ok, I can do that.

The end of the cable needs to be cut at specific lengths, correct?
what do you mean by specific lengths, Shouldn't you just be able to shorten the cable as much as needed? as long as you dont have any excess with no tight bends and I think you should be fine
 
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what do you mean by specific lengths, Shouldn't you just be able to shorten the cable as much as needed? as long as you dont have any excess with no tight bends and I think you should be fine
I’m talking about the end that mates to the new connector. Doesn’t the center piece that gets soldered on have to be a certain length, then the insulator a certain length, etc.
 
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Reminds me of a story. Years back, a woman co-worker - who I'd known for MANY years, and I'm still in contact with - was walking me through wiring up a particular brand/type of BNC coax connector. At one point, she told me to "shave just a tiny bit off"... Of course, you know what I was thinking - then she said "One of them thar blonde ones!". :ROFLMAO::ROFLMAO::ROFLMAO:
 
I just remembered, my cable has the fire ring on the end, not a PL-259.
 
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