CB questions

[Apexdisco]

What gives you the maximun range with a cb radio? Is it the radio itself or the size of the antenna?

For the Firestix's product, what's the most popular size? Six feet?

There was a guy making a cb mount for the center console? Anyone remember his name and if he's still selling these?

Can you guys post some pictures of your cb radio mounted to the inside? Thanks!

 

[Morpheus]

Kris,
Not to get off your topic but when you lifted your Disco do you remember what size thr Rear retaining hardware was? did you have to replace yours? I emailed you so you can just delete it. Im hoping to do mine this weekend and would like to have extra bolts onhand just in case

 

[Joey]

Antenna helps a lot, but true range comes for the output of the radio (legally all US Spec radio's can only produce 4 watts). If you radio is tuned up or you run a linear amp, you will get better range from you radio. But if you really want range, forget the CB, and get a 2 meter radio or something similar.

Just my .02 worth

 

[eburrows]

Several factors contribute to CB range and clarity:
1. Antenna radiation pattern
2. Antenna's ground plane
3. Output power
4. Noise

First, you have to realize that CB is a pretty crappy medium for several reasons: It uses normally uses AM modulation, which is very susceptible to interference. When you listen to an AM broadcast, any other broadcast on or very near that frequency is picked up as well. (Unlike FM modulation) CB is also a very low frequency, making it travel well, and bounce off things well. This would be good normally, but there are thousands of CBs all around, making the noise level just that much worse. Also, as alluded to above, many people use amplifiers on their radios, which increase interference, and add their own noise into the signal. (And often widen the bandwidth of the signal, causing interference on nearby channels.

To get the most ouf of CB, I would focus more on numbers 2 & 4 on the above list. Any good fibreglass CB antenna is going to be good. Keep away from the steel whip antennas, their flapping about only makes things worse. To keep noise to a minimum, use good co-ax cable, mini-8 is good stuff, and sold everywhere. Run power to your radio either direct from your battery, or through a noise filter, or both.

Ground plane is the most often overlooked item with CB. Nearly all antennas need a good ground plane to work, including all CB antennas you find in stores. You can have a $200 antenna, but if you clip it to a bar sticking out of the side of your truck, it'll work like crap. To get the good radiation pattern you want, there needs to be a nice flat piece of sheetmetal under the antenna. The more flat, (actually 45 degrees downward is best) and the wider the better. Smack-dab in the middle of your roof would be best. The less ground plane, the less your antenna will transmit in the direction (along the ground) that you want.

For my three antennas (CB, 144/440mhz and 50mhz, I used two roof rail cross-bars to support a ground plane sheet, onto which I installed my antenna mounts. If you are OK with drilling into your roof, that would be even better. If you really must attach your antenna to a ladder or roof rack, try to get one of the false ground plane devices, which have three pieces of wire sticking out in a triangle shape under the antenna.

 

[DiscoveryXD]

 

[bshinn]

Is CB a dying mode of communication? I bought a Cobra & think it's worthless. I'm sure it needs to be tuned, but the the shortcomings are well documented. Is FRS/GRM the wave of the future? Those small handhelds w/ a 5-10 mile range seem to be pretty impressive for general trail use unless they are lie of sight.

 

[eburrows]

I think FRS is a great alternative to CB. It is line-of-sight, and you're stuck with batteries, but you get a lot of the benefit of 2m ham, without having to take an hour-long exam to qualify! FRS is FM, so it sounds a lot better, and generally the power and range limit isn't a big deal, especially if you're lined up on a trail!

 

[asurover]

i don't have any pictures but i think the best place to put the cb is on the center console storage compartment so it sits next to the seat, most cb's will come with the mount you need to put it there. i have a six foot firestik mounted to the rear bumper and i like it. i have the cobra 19dx and love it, plus they are only about 40 bucks at most truck stops.

 

[ptschram]

But if you really want range, forget the CB, and get a 2 meter radio or something similar.

Just my .02 worth

Wrong! VHF is line-of sight. The only reason you get more coverage with VHF is due to the use of repeaters. If you'r ein the middle of nowhere, and there isn't a repeater, if you can't see it, you can't talk to it. If you're in a valley, you're not gonna talk beyond that valley. If you're on a mountaintop, you'll have better coverage.

 

[ptschram]

Several factors contribute to CB range and clarity:
1. Antenna radiation pattern
2. Antenna's ground plane
3. Output power
4. Noise

First, you have to realize that CB is a pretty crappy medium for several reasons: It uses normally uses AM modulation, which is very susceptible to interference. When you listen to an AM broadcast, any other broadcast on or very near that frequency is picked up as well. (Unlike FM modulation) CB is also a very low frequency, making it travel well, and bounce off things well. This would be good normally, but there are thousands of CBs all around, making the noise level just that much worse. Also, as alluded to above, many people use amplifiers on their radios, which increase interference, and add their own noise into the signal. (And often widen the bandwidth of the signal, causing interference on nearby channels.

To get the most ouf of CB, I would focus more on numbers 2 & 4 on the above list. Any good fibreglass CB antenna is going to be good. Keep away from the steel whip antennas, their flapping about only makes things worse. To keep noise to a minimum, use good co-ax cable, mini-8 is good stuff, and sold everywhere. Run power to your radio either direct from your battery, or through a noise filter, or both.

Ground plane is the most often overlooked item with CB. Nearly all antennas need a good ground plane to work, including all CB antennas you find in stores. You can have a $200 antenna, but if you clip it to a bar sticking out of the side of your truck, it'll work like crap. To get the good radiation pattern you want, there needs to be a nice flat piece of sheetmetal under the antenna. The more flat, (actually 45 degrees downward is best) and the wider the better. Smack-dab in the middle of your roof would be best. The less ground plane, the less your antenna will transmit in the direction (along the ground) that you want.

For my three antennas (CB, 144/440mhz and 50mhz, I used two roof rail cross-bars to support a ground plane sheet, onto which I installed my antenna mounts. If you are OK with drilling into your roof, that would be even better. If you really must attach your antenna to a ladder or roof rack, try to get one of the false ground plane devices, which have three pieces of wire sticking out in a triangle shape under the antenna.

Eric-lemme guess, you have a no-code ham license, right? Bad enough they went to no-code, but now you only need 5WPM for extra.

AM is limited by the fact that most noise is amplitude modulated. Natural and man-made. The fact of life is that spontaneous oscillations are AM.

Ground Plane? Go read up on just what a ground plane is. You do not need a given size or shape of material to result in a good ground plane. Good connection to the ground of your truck will provide you with a suitable counterpoise. False ground plane of three pieces of wire sticking out beneath your antenna-that is the definition of a groundplane for a freestanding vertical antenna. Lastly, these three pieces of wire (actually, the more the better) must be at least 109" long (at 11 meters) to be effective.

A fiberglas antenna is a horrible compromise. The best performance will be achieved by using a full quarter wavelength antenna and not a loaded short antenna. Believe it or not, this is the largest reason for poor performance both receiving and transmitting. If you want ot hear and be heard, run a full size quarter wave antenna.

Peace,
PT
WD9HRP-Extra Class since before April 15

 

[Joey]

P. T. Thanks for the info... I know alot more about CB stuff then I do HAM type info... I probably could have called my brother in Florida and would have typed a story, but didn't want that much info...just trying to help... I just know that CB's are limited and you are better off with a HAM type Setup.

Can't remember my brothers call letters, but I know he passed the (I think 25 or 30 WPM) like 16 years ago.

Of course he also has been into the CB/HAM stuff since he was in his teens.

 

[eburrows]

Paul,
I'm sorry, you're right, my no-code tech license makes me inelegible to give helpful comments about radio setup. Of course, if I could tap out morse code at 20 WPM, I could be much more helpful with CB installations.


And to be correct, the statement "AM is limited by the fact that most noise is amplitude modulated. Natural and man-made. The fact of life is that spontaneous oscillations are AM." is false. AM stands for "Amplitude Modulation". Most natual and man-made noise is not modulated at all, they tend to be relatively stable at one frequency, and at one amplitude. AM is limited by this noise, because it receives any and all signals within it's bandwidth. FM, having greater signal selectivity, is much less affected by these normally low-power emissions.

Secondly, yes, the shape and size of an antenna's ground plane does affect the radiation and reception pattern of an antenna. As you may have seen above, asurover mounted his antenna onto his rear bumper. I'm sure the connection to ground is good, but it is not, as you said "Good connection to the ground of your truck will provide you with a suitable counterpoiss". His radiation pattern will at best be only 275 degrees in the horizontal, and the side of the truck running right up next to the antenna will certainly affect everything from pattern to tuning capability.

 

[Rover Puppy]

CB's are not a dying mode of communication.

After the hurricanes hit, we went into many of the worst hit areas to provide disaster relief and assist with the recoveries. Those of us with CB's in our trucks were the only ones who had immediate and consistently reliable communication capability. This remained true even weeks after the disasters when progress was being made restoring the infrastructures.

Before the hurricanes, I didn't place much value on my CB. Now, if I had to make the choice between my CB and my cell phone, I'd ditch my cell phone in a heartbeat.

We also learned that cash is not a dying form of currency when you're fortunate enough to find fuel post disaster. When things get bad, it's the old stuff that still works

Good Luck, Jamie

 

[JSQ]

I also have to disagree with some of the above.
VHF doesn't entirely operate under line of sight limitations. Outside of a lame frequency range the main reason CBs suck so bad is their limited Tx power as mentioned above. A good HAM mobile will do 65 watts. Then you are pushing a signal like that you can be heard irrespective of the next hill.
That's not tech, that's just experience.
A good antennae and high wattage broacast and I'm gonna hear ya.

GMRS and 440 are nice alternatives to licensing.

 

[SandMan]

Boys, leave the CB to Smokey and the Bandit. Get yourself a Satellite Phone. As long as I'm not within 1000 miles of either Pole, I can talk to anyone I want. My line of sight is practically unlimited! No mounting brackets, no antenna worries, no sweat!

Choose from GlobalStar, Iridium, Thuraya and others. If you really need to call and get help in an emergency, there is no better feeling that that phone sitting in your cubby box. I have Thuraya, for obvious location reasons, and it works great.

For two way comms on the trail, I like the Motorola T7100 handhelds with 7 mile (more like 5 mile) range. Don't need much more than that (unless your buddy is lost) and it comes with a cigarette lighter adapter cord. Besides, I can take them with me hiking and use them at the mall. Can't do that with your 12V mounted CB or HAM.

Add the Garmin GPS and there you have it, SandMan's complete bag 'o tricks!

 

[utahdog2003]

What gives you the maximun range with a cb radio? Is it the radio itself or the size of the antenna?

For the Firestix's product, what's the most popular size? Six feet?

There was a guy making a cb mount for the center console? Anyone remember his name and if he's still selling these?

Can you guys post some pictures of your cb radio mounted to the inside? Thanks!

Tune the antenna and use a little common sense. Buy a 2 foot fire stick for the bumper that doesn't clear the roof of your truck and you'll get crappy response. Put the same ON the roof and you'll be fine.

as for Sat Phones. Well, lets just say they are probably more usefull in the UAE than in North Carolina.

 

[ptschram]

I also have to disagree with some of the above.
VHF doesn't entirely operate under line of sight limitations. Outside of a lame frequency range the main reason CBs suck so bad is their limited Tx power as mentioned above. A good HAM mobile will do 65 watts. Then you are pushing a signal like that you can be heard irrespective of the next hill.
That's not tech, that's just experience.
A good antennae and high wattage broacast and I'm gonna hear ya.

GMRS and 440 are nice alternatives to licensing.

Above 144 mhz, propagation under the vast majority of conditions is limited to line of sight (horizon) plus 3 degrees. Tunneling, inversions, etc are rare occasions and should not be relied upon for reliable communications.

CB is not a lame frequency. All frequencies below 30 mhz can be used for world-wide communications and regularly are. MANY hams use extremely low power levels and conduct reliable communications over very long distances.

The amateur regulations require one to use the minimum power necessary to maintain communications.

Propagation and radiation pattern distortion from local conductive bodies is not a ground plane issue, but capacitive or inductive interference-again, not a ground plane issue.

Natural noise (with the exception of some piezoelectric oscillations) are absolutely broadbanded, not single frequency-lightning is a good example and sparks are even better, hence the outlawing of DC to daylight spark-gap transmitters popular in the dawn of radio.

Verticla antennas and a mobile environment force many unsuitable compromises to be made. Understading the theory and practice of electronics and radiowave propagation will go a long way to overcoming these compromises.

Peace,
PT
WD9HRP

 

[koby]

For two way comms on the trail, I like the Motorola T7100 handhelds with 7 mile (more like 5 mile) range. Don't need much more than that (unless your buddy is lost) and it comes with a cigarette lighter adapter cord. Besides, I can take them with me hiking and use them at the mall. Can't do that with your 12V mounted CB or HAM.

Satellite phone is nice, but I think my Yaesu FT-60R will blow away your T7100 FRS/GMRS units if only for the simple reason that the Yaesu HT can hit repeaters.

 

[syoung]

Yeasu FT 60R- $225
Motorola T7100 - $50
SS66K Iridium Satellite Phone - $599
Cobra 18 CB with WX- $65

Personally, I use a Yaesu 50 watt dual bander and CB in the truck and Motorola T7200 on foot. Since everyone has a different preference, when meeting up with others you kinda need to have both CB and FRS/GMRS. I've yet to go on a group ride where everyone all had the same type of radio.

 

[koby]

Ah, but what about modding the FT-60R to dx at FRS / GMRS frequencies?