CB Radio/Antenna - need more power

[chadbyoung]

Hello all

- A little back ground

I recently purchased a new antenna, mount, and cable for my CB (Uniden 510XL, its cheap but it gets the job done) . I purchased a firestik II antenna and 18ft of RG58 cable.

I made, what I think are, all correct connections. I have made sure that I had continuity in all the right places and the mount was grounded.

I then tuned the antenna/cb with a SWR meter:
Chan 01 = 1.2 ~ 1.5
Chan 19 = ~1.2
Chan 40 = 1.2 ~ 1.5

So all seems good right? - Well maybe.

- The question

When I am transmitting, on channel 19, I see that the power is only reaching 2.5 ~ 2.7 watts. I read that the CB has a max output of 4 watts. So why am I not transmitting at the max power?

Any ideas?

Thanks
Chad

 

[wa8pyr]

Hello all

When I am transmitting, on channel 19, I see that the power is only reaching 2.5 ~ 2.7 watts. I read that the CB has a max output of 4 watts. So why am I not transmitting at the max power?

Chad;

Actually, your power output is just about right.

Your CB uses Amplitude Modulation, and maximum power is only reached on voice peaks. You can enhance your power output somewhat by using a compressor between the mike and the radio, which will compress the voice signal, make slightly better use of the radio's power amplifier and get a bit more out of your signal.

The problem is, compressors are kind of tough to set up correctly. Too little compression and you don't do much good. Too much compression and your signal sounds mushy and unintelligible.

CBers also use "power mikes", which are nothing more than microphones with preamps between the mike and the radio. Here, too, incorrect adjustment can ruin your signal with too much or too little amplification, and can actually overdrive the radio, making it splatter into adjacent channels; this is a sure way to enrage your fellow CBers.

Also beware of "echo boxes" and "roger beeps"... all alter the audio signal, and every gadget you put between the mike and the radio detracts from your audio quality.

You're really best off leaving well enough alone and making do with the best antenna system you can put together; judging by your SWR readings you're doing pretty well.

Tom WA8PYR

 

[ReceiverBeaver]

Hi guy,

If you don't mind the length, your best bet on an antenna would be a good 'ol 102" stainless steel whip. This is a 1/4 wave ground plane on 11 meters (CB). This design has the widest resonant bandwidth of any antenna for your type of mobile setup. It will cover the entire 11meter band and beyond with a 1:1 flat SWR. It'll also have the best reception as you have more (longer) antenna in the air to pick up signals. In Radioland generally, longer and higher are always better.

If you try one, be sure to obtain a 102" whip. I think the one Radio Shack and some other sellers offer is 96" long. These are made-tuned for the 10meter ham band right above the CB channels and likely will not provide a 1:1 SWR down on the CB channels. Sometimes they can be adequately extended by adding one of those large size springs on the bottom. The spring will be in the radiating circuit and are about 6 inches long give you the extra needed length.

Good luck. The Beaver here is a ham and CB'er since the mid '70s.

 

[prcguy]

Watt meters in CBs are simple diode detectors and calibrated at the factory into a dummy load. They will read all over the place with different antennas and frequencies due to varying loads at the antenna jack and that’s normal even though your power is fairly constant. In other words, ignore the meter in the CB unless it stops moving completely.
prcguy

 

[N_Jay]

And one other thing.

Changes less than 3 dB really don't even matter.
Most people could never tell the difference between 2 W and 4 W.

 

[freqs]

Hello all

- A little back ground

I recently purchased a new antenna, mount, and cable for my CB (Uniden 510XL, its cheap but it gets the job done) . I purchased a firestik II antenna and 18ft of RG58 cable.

I made, what I think are, all correct connections. I have made sure that I had continuity in all the right places and the mount was grounded.

I then tuned the antenna/cb with a SWR meter:
Chan 01 = 1.2 ~ 1.5
Chan 19 = ~1.2
Chan 40 = 1.2 ~ 1.5

So all seems good right? - Well maybe.

- The question

When I am transmitting, on channel 19, I see that the power is only reaching 2.5 ~ 2.7 watts. I read that the CB has a max output of 4 watts. So why am I not transmitting at the max power?

Any ideas?

Thanks
Chad

are you intrested in putting 40 bucks in that radio have in tuned set up for a amp even if dont wish to use 1 in will bring up your receive and alow full modulation any truck stop with a repare shop can do it or cb shop i run a 148 gtl had the mod cut set up for a amp i can talk to texas from detroit no amp and i like the wilson anttena the best but i do use a k40 and a cobra 6000 watt mag mount a good power mike helps as well you want go cheap get a better antenna it is all in the antenna but you got a good match so that is key radios stock are not pumping out full wattage from factory 1 thing to think of good luck

 

[jhooten]

Was the car running or were you just running off of the battery? Some CBs are pickey about voltage. If you were on the battery and the radio was only getting 12 volts that could be one part of the low power problem. With the car running and the radio getting the full 13.8 volts from the alternator your power may go up a smidge.

 

[N_Jay]

are you intrested in putting 40 bucks in that radio have in tuned set up for a amp even if dont wish to use 1 in will bring up your receive and alow full modulation any truck stop with a repare shop can do it or cb shop i run a 148 gtl had the mod cut set up for a amp i can talk to texas from detroit no amp and i like the wilson anttena the best but i do use a k40 and a cobra 6000 watt mag mount a good power mike helps as well you want go cheap get a better antenna it is all in the antenna but you got a good match so that is key radios stock are not pumping out full wattage from factory 1 thing to think of good luck

Do you speak that way? :roll: :lol:

 

[scansomd]

I think this post 'speaks' for itself. In case you missed the message, here it is:

Stay far, far away from truck stop CB 'repair/modification' shops.

are you intrested in putting 40 bucks in that radio have in tuned set up for a amp even if dont wish to use 1 in will bring up your receive and alow full modulation any truck stop with a repare shop can do it or cb shop i run a 148 gtl had the mod cut set up for a amp i can talk to texas from detroit no amp and i like the wilson anttena the best but i do use a k40 and a cobra 6000 watt mag mount a good power mike helps as well you want go cheap get a better antenna it is all in the antenna but you got a good match so that is key radios stock are not pumping out full wattage from factory 1 thing to think of good luck

 

[daktony]

Hey Chad,

Im Big Into Cb Radio Because I Drive A Truck. When You Bought The Cb, Did You Have It Peaked And Tuned? That Provides The Maximum Transmit And Receive The Radio Can Do Without Sounding Bad Or Hurting It. Basicly You Bought The Lowest End Cb And A Fiberglass Antenna. Me Personaly On A 4wheel Vehicle Your Best Bet Is To Send $20 And Get A 102" Whip Which Will Help Alot With Transmit And Receive, But Watch Out With The Drive Thru Windows! If You Want To Spend Money $100 Can Get You A 90watt Increase With A Texas Star Modulator. Just Stay Away From The Off Brands. If You Want A Bigger Cb Go With A Dual Final Radio Such As A Connex 4400hp Or Bigger Connex 3300-300 , That Does 300 Watts By It Self But Has To Be Hooked Up Directly To The Battery. Hope This Helps

 

[jonny290]

That's the longest book title I've ever read.

I'd be pleased to see RadioReference admins ban these people who bring up CB amps or 'peaking and tuning'. Newsflash, truckers - those finals are designed for X *clean* watts. After you 'peak' they spit out harmonics and piss everybody off. But hey, you don't give a damn, you just keep on drivin down the road wiping out TV sets.

 

[W9GC]

But hey, you don't give a damn, you just keep on drivin down the road wiping out TV sets.

Will do. Thanks for the permission.

 

[kb2vxa]

Chad, those CB power meters are calibrated as well as the average sausage. As long as you're "getting out" don't worry about it. Frankly I wouldn't use one of those "power mics" because all they do is overdrive the audio and over modulate causing distortion and splatter on adjacent channels. The stock mic is quite adequate despite the fact they'll tell you that you have low audio, they're used to hearing the meat grinders.

To sum up a few comments I've read, keep the "golden screwdriver" out of the rig. "Tweaking and peaking" buys you nothing but trouble unless it's done properly by the only one authorized, the holder of an FCC GROL license. Most rigs don't live up to their potential because of the way they're manufactured but are "good enough for government work" (too much detail to go into here) but a qualified technician can bring it up to snuff without voiding the FCC certification and getting you and himself in trouble. Yup, the license must be protected, he's responsible for insuring compliance.

The above paragraph is just for your information if you feel you feel you can't resist and absolutely must tinker with the radio. When all is said and done follow the golden rule of all things mechanical and electrical, if it ain't broke don't fix it.