Cb Radio Advice

I installed a Cobra CB in my F-250 last winter. I am not one to talk on it much, I mainly listen. I seem to get a lot of intereference from the electronics in the truck, blower motor, power windows, power seat, all make loud noises through the speaker.

I am also not convinced anyone can hear me. I can hear them, if they are within a mile or so, but i've talked and no one responded... Makes me wonder if they can even hear me!

I have it setup with a thru the glass antenna. I did not want to put a hole in the cab to run the wire. I am curious as to if this is my problem.

http://cobra.com/index.cfm?fuseaction=product.display&Product_ID=232&category_ID=30

That's what I have.

Should I install a taller external antenna or am I supposed to program this CB somehow?

Hey I have that exact radio in my ranger. I'll tell you, mine don't work that great either. My range is about the same, 1 mile. It is more a function of the small size of the radio then the antenna. The only way to improve performance is to get your antenna tuned but it sounds like you have a weird one in your window and this might not be possible. These radios suck, I am sad to say. The best radios made are a Cobra 25, these are a little bigger and much better. The problem with ours is that they cannot be "peaked and tweaked," which is truckdriver for getting it cranked up internally by a specialist. These CB repair shops are getting harder to find too. I highly recomend the Cobra 25.

Try this link, don't know if it works- http://cobra.com/index.cfm?fuseaction=product.display&Product_ID=315&category_ID=30

i know if your ground and positive wires are to close to each other that can happen, you can try to center your whip in the middle of your truck. theres only so much it could be you know..

Damn, I figured you all were going to tell me that!

Too bad I cut out the cubbie in the dash to fit this one in.. Looks like I will just be stuck with what I have!

my cheap radio shack gets peaple up to 30 miles away never had any problems with it.

weel first of all you can buy a module to kill the noise at any truck stop. for reception check your anntena location if there is any metal near it there will be interferance. another thing you can do is put dual anntenas on the truck this will push your power in a larger arc. second find a local cb shop and have your anntenas tuned to match your cb along with your coax. the things that make a cd work the best are: tuning the cd, match the length of the coax to the cd power, eliminate interferance, and tune your anntenas to match cb power. if you get a higher quality cb alot of this will be easier because you can adjust your SWR and calibrate your cd your self i would get a cobra 29 with sound tracker. cb's can rack up the $ really quick if you wanna blow peoples doors off. i have about 350$ in mine with a booster and can reach over 100 miles on a good day. the best thing you could do is go to a cb shop and talk to them they can fix the whole thing with in 20 min i bet or at least tell you what you need to do exactly.

Jspafford, I got an extra radio, much better quality too, I think it's a 29 ltd Nightwatch. I could hook ya up with, even come down and get it hooked up and tuned in for ya if ya want. would be willing to part with it for say 150 which would include gas and tuning, and a beer or two.

oh yea those thru the glass antennas suck @$$, as far as an antenna mounting option check out this bad boy!! I'm gonna order one for my truck!

i would make a bracket like that for 25$ lol. and you dont want steel it could ground out the antenna. go with aluminum.

I have it setup with a thru the glass antenna. I did not want to put a hole in the cab to run the wire.

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and THAT IS THE PROBLEM, really look into a magnet mount antenna, a wilson or K-40 would do, or if you don't want to risk leaving a spot where the magnet sits(they will scratch over time) consider drilling a hole in the roof and using a hersey kiss mount, or perhaps some fiberglass antennas mounted on the mirrors, J.C. whitney also has adaptors so you can use your Am/fm antenna for your CB.

a thru-glass antenna is useless at CB frequencies. The key to a sucessful moblie CB installation is getting a good antenna setup, so you can basically squelch out the power line noice, etc. and still be able to listen and talk to another station.

I also have the same radio in my Ranger, and mine also is horrible at picking up signals. I have a 3ft Magnet mount in the center of my roof, and I tuned it, but it only worked good for a couple days before it was right back to normal. I was thinking of getting a fiberglass antenna from my local radio shack, and by the looks of that bracket I'll be making one of those. I have an aluminum cap on for part of the year, would that have any effect on it?

Let me know if you ever get it to work right.

Maybe just the radio.

Magnetic mounts are a compromise. Ideally, a direct connection to ground at the base of the radiating element is best, although there is some "magnetic coupling" to the vehicle with a magnetic mount. If you want the best bang for you buck and don't want a 9ft whip sailing above your truck, try something like a shortened 5/8 wave vertical. Electrically, they are a 5/8 wave, but don't quite have the gain of a true 5/8 wave. Even if mounted off-center, one of these will outperform a magmount centered on the top of the vehicle. You can find these at any truck stop or CB shop. Most of the major antenna manufacturers make them. Performance is going to be the relatively the same from brand to brand. They range from 3-6 ft, and are constructed with wire would around a fiberglass whip, sealed in plastic. There are mounts you can slide in to the stake holes along the side of truck bed, so no external drilling, although I would drill a small hole in a concealed location to make a good bond to ground, which is extremely important.

If you are experiencing static and noise from the vehicle, try wiring the radio directly to the battery. This is good installation practice, and recommended by Ford as the first thing to do to resolve vehicle-generated noise. This includes both positive and negative leads. Quite often noise is propagated through the wiring and into the radio. Most of the filters are designed to filter voltage fluctuations, which is what you hear from an alternator, and are not designed to be common-mode filters.

reginald fairfield said:

Hey I have that exact radio in my ranger. I'll tell you, mine don't work that great either. My range is about the same, 1 mile. It is more a function of the small size of the radio then the antenna.
http://cobra.com/index.cfm?fuseaction=product.display&Product_ID=315&category_ID=30

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The size of the radio has nothing to do with it. Assuming his radio has 4 watts output, the antenna, feedline, or coupling to ground is the problem.

Muddycowboy said:

second find a local cb shop and have your anntenas tuned to match your cb along with your coax. the things that make a cd work the best are: tuning the cd, match the length of the coax to the cd power, eliminate interferance, and tune your anntenas to match cb power. if you get a higher quality cb alot of this will be easier because you can adjust your SWR and calibrate your cd your self i would get a cobra 29 with sound tracker. cb's can rack up the $ really quick if you wanna blow peoples doors off. i have about 350$ in mine with a booster and can reach over 100 miles on a good day. the best thing you could do is go to a cb shop and talk to them they can fix the whole thing with in 20 min i bet or at least tell you what you need to do exactly.

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Antennas aren't tuned to match a transmitter, or the feedline. Well, you can "do" the latter, but it isn't the proper way to do things. If you have an antenna with a single driven element, you connect the SWR bridge as close to the antenna feedpoint as you can, tune the antenna, then connect the coax. If you are using two driven elements, do the same for both, then calculate the length of coax you need in relation to the frequency, and don't forget to include the feedline's velocity factor in this calculation.

Muddycowboy said:

cb's can rack up the $ really quick if you wanna blow peoples doors off. i have about 350$ in mine with a booster and can reach over 100 miles on a good day. the best thing you could do is go to a cb shop and talk to them they can fix the whole thing with in 20 min i bet or at least tell you what you need to do exactly.

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Amplifiers are for people that are trying to compensate for the shortcomings of their installation. A properly installed mobile with 4 watts AM should have a range out to about 10-15 miles groundwave (not skip). SSB will work out to about 15-20 miles. I've talked out to all 50 states, Guam and most of Canada with 4 watts. I've talked out to Australia, New Zealand, Thailand, Italy and quite a few more places on SSB with 12 watts PEP. I was using a 4ft Firestick for an antenna, which was mounted 4 inches behind the cab of the truck.

Whats the point of a cb radio nowadays?

michowski said:

Whats the point of a cb radio nowadays?

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I use mine to listen for smokey reports a lot... You just have to put up with these new age truckdrivers who like to cuss a lot. They don't know what driving a truck for 35 years is like... Cocky little shits.

Yeah Bill, I agree with you that the size is not the problem, but little radios offer less oppurtunities to be peaked and tweaked internally. The 19s can't be tuned at all, according to the local shop. Like I said, the 25 Cobra is the best bang for the buck if ya'll want my opinion.

Peak and tweak what?

So you can increase the output from 3.7 watts to 5? Doubling power output will give you 3 dB gain. That is barely noticeable.

So you can crank up the modulation from 90 % to 120%? Sure, it makes you sound louder, but there is a reason the modulation circuit has a limiter, and that is to prevent distortion. Splatter, or "bleedover" from other channels is the result of this distortion. If you want pure modulation use SSB, which will give you 9 dB of gain at the transmitter, plus a receiver with a much better S/N ratio.


If you (and others) want some good and straightforward technical information on this stuff I suggest buying a copy of the ARRL Amateur Radio Handbook. The current copy is a little expensive, but you can pick up older copies for less than $5.00 if you look hard enough. Any edition from the last ten years will be adequate.

http://www.amazon.com/s/ref=nb_ss_gw/105-8567612-5418027?url=search-alias%3Daps&field-keywords=amateur+radio+handbook&x=0&y=0

There is also an Antenna Book published every few years that goes explains quite a bit about antennas, transmission lines and radio propagation.