Need advice on CB radio and 1 or 2 whips?
Need advice on CB radio and 1 or 2 whips?
So Im looking into a CB radio setup and d'uh, I dont know a thing about them. Can anybody give me some basic knowledge and what to look for? I will likely buy it used but I would like to know some do's and dont's and what to look for and what to stay away from.
Also, is there any advantage to having 2 whips versus 1? I like the look of 1 on eack side of the bad rail. Thanks guys!
Also, is there any advantage to having 2 whips versus 1? I like the look of 1 on eack side of the bad rail. Thanks guys!
Member
Joined: Nov 2012
Posts: 67
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If you want looks, go dual.... if you want optimum performance and good SWRs, go single.
If you want power, get a HAM radio with dual finals, converted to CB, peaked and tuned.
Don't use cheap coax and don't coil the excess around itself, run it around the interior of the cab.
If you want power, get a HAM radio with dual finals, converted to CB, peaked and tuned.
Don't use cheap coax and don't coil the excess around itself, run it around the interior of the cab.
Senior Member
Joined: Jul 2004
Posts: 6,200
Likes: 39
From: Easton, Pa.
You may like the looks but from a technical point, two don't work any better than one.
This gets a bit deep so i'm not sure you want to hear about it.
Put two on if that's what you want.
Ususally called co-phasing (a missnomer by the way) they must have certain length coax cables to obtain an electrical match for the radio.
Once you get them in place it pays to use a meter to adjust driven elements lengths for the best match on channel 20 or a balance between channel 1 and 40 for the same sleightly higher reading below 3 to 1 on both ends of the band...
The meter used is called a Standing Wave Ratio meter or SWR for short.
It reads the return or reflected power due to missmatch.
It's this missmatch your wanting to get as low as possible or below a ratio of no more thn 3 to 1.
Going on a bit more, two antennas mounted as such has a distorted radiation pattern as opposed to one setting in the middle of the cab roof.
The biggest reason why two mounted as such don't have much advantsge is because at the frequencey being used you can't get then far enough apart.
Said another way, the spacing should be 1 quarter wave length.
This is about 8 feet on the CB band.
Your mounting locations are not 8 feet apart on a pickup or a car.
On a big tractor it's a different story for mirror to mirror distance and why you see them on big trucks.
I hope I at least gave you some sense of it all.
Good luck, from a Ham.
This gets a bit deep so i'm not sure you want to hear about it.
Put two on if that's what you want.
Ususally called co-phasing (a missnomer by the way) they must have certain length coax cables to obtain an electrical match for the radio.
Once you get them in place it pays to use a meter to adjust driven elements lengths for the best match on channel 20 or a balance between channel 1 and 40 for the same sleightly higher reading below 3 to 1 on both ends of the band...
The meter used is called a Standing Wave Ratio meter or SWR for short.
It reads the return or reflected power due to missmatch.
It's this missmatch your wanting to get as low as possible or below a ratio of no more thn 3 to 1.
Going on a bit more, two antennas mounted as such has a distorted radiation pattern as opposed to one setting in the middle of the cab roof.
The biggest reason why two mounted as such don't have much advantsge is because at the frequencey being used you can't get then far enough apart.
Said another way, the spacing should be 1 quarter wave length.
This is about 8 feet on the CB band.
Your mounting locations are not 8 feet apart on a pickup or a car.
On a big tractor it's a different story for mirror to mirror distance and why you see them on big trucks.
I hope I at least gave you some sense of it all.
Good luck, from a Ham.
awh, frigg haha. Im kinda lost. I understand a bit but just not sure what to look for in a the cb unit itself. Ill stick with the single roof mounted whip. Im gonna read up on these cb units and try to understand more. I'm a metal fabricator by trade and never really got into radios and wiring other than simple switches and decks. Thanks for the input tho guys.
Senior Member
Joined: Jul 2004
Posts: 6,200
Likes: 39
From: Easton, Pa.
A good mag mount antenna of the longer element type will do fine.
Many AM radios today are very inexpensive at less than $50 for an entry level radio.
Cobra is a well known brand.
Sorry to do that to you. Don't get excited, it's not that bad.
I was trying to show that there is some science to it like any other 2 way radio if you were wondering.
Good luck and enjoy.
Many AM radios today are very inexpensive at less than $50 for an entry level radio.
Cobra is a well known brand.
Sorry to do that to you. Don't get excited, it's not that bad.
I was trying to show that there is some science to it like any other 2 way radio if you were wondering.
Good luck and enjoy.
Senior Member
Joined: Mar 2013
Posts: 170
Likes: 0
It's been a while (30+ years) since I had a CB radio so advances may have passed my knowledge and negate my suggestion below.
I concur with the above, for smaller vehicles one antenna is better than two. The key (ages ago anyway) was as noted, getting a meter and tuning the antenna.
And it's best to mount it as high and centered as possible. You get a better (smoother? more even? longer?) signal range than mounting it low and off the side. The metal of the vehicle shapes/deforms the field. Ideally, top and center of the cab roof is best, but that might not suit your style. It's not a huge difference to compromise with a different mounting point.
I never trusted the magnetic mounts myself. Seemed like they were just begging to be pulled off by punks, branches, wind, and whatever.
Myself, and I'm not sure they are still available but they used to be, I'm going to have a look for a combo AM/FM/CB antenna that replaces the factory AM/FM antenna. It means less work installing and nobody will know I have the CB inside... Style and Stealth
...though maybe a little less range.
I concur with the above, for smaller vehicles one antenna is better than two. The key (ages ago anyway) was as noted, getting a meter and tuning the antenna.
And it's best to mount it as high and centered as possible. You get a better (smoother? more even? longer?) signal range than mounting it low and off the side. The metal of the vehicle shapes/deforms the field. Ideally, top and center of the cab roof is best, but that might not suit your style. It's not a huge difference to compromise with a different mounting point.
I never trusted the magnetic mounts myself. Seemed like they were just begging to be pulled off by punks, branches, wind, and whatever.
Myself, and I'm not sure they are still available but they used to be, I'm going to have a look for a combo AM/FM/CB antenna that replaces the factory AM/FM antenna. It means less work installing and nobody will know I have the CB inside... Style and Stealth
...though maybe a little less range.
Thanks guys, Ive been reading into how these work and about the tuned whips and boosters and am definately understanding what you guys were saying now. Unfortunately I think I am going to hold off for now. I wanted the set up mainly to have for when Im up north messing around in the rig as a bunch of guys have them up there but not a huge need for it in the city. Ill still likely install one at some point, just not right now. Thanks again for your input, I appreciate it.
