Touchy subject.. Tuning cb's

[ZombieSoldier01]

I know, I know the FCC Nazi Ninja's will come cart me away if I tune my radio, blah blah blah. Has anyone here ever done one on a Cobra 29LTD Classic? If so do you have a tutorial, or can walk me through doing it? I want to increase my power due to the topography of my area (colorado rockies)

[Bunsen]

If so do you have a tutorial, or can walk me through doing it? I want to increase my power due to the topography of my area (colorado rockies)

1.) No discussion of illegal activities as a viable option.
No.

If you want to find information on modifying your radio to transmit at illegal power levels, you can do it somewhere else. We don't instruct people on how to break the law here.

[Grey Mann]

For what it's worth, tuning a cb =/= illegal modifications of power capabilities. You tune a CB radio with an SWR meter, adjusting the length of your antenna to get the SWR to the lowest value possible.

Seriously, though, what's the deal with all these members lately trying to post around the rules?






Go HAM or go home, if you want more power.

[American_Infidel]

Look into high gain directional antennas for reliable communications with a CB. Tuning it might be the easy way out, but most altered CBs splatter something awful causing issues with the other station trying to copy. Plus it bleeds over to other CB channels and even over to other bands (like 10m).

[TacAir]

I know, I know the FCC Nazi Ninja's will come cart me away if I tune my radio, blah blah blah. Has anyone here ever done one on a Cobra 29LTD Classic? If so do you have a tutorial, or can walk me through doing it? I want to increase my power due to the topography of my area (colorado rockies)

(You may have to look some of this 'stuff' up, do so, it will be a good way to learn more about your radio). About the FCC. They issue something called "Notice of Apparent Liability for Monetary Forfeiture". These babies are sent by the FCC's Enforcement Bureau. The fines start in the thousands of dollars. Word to the wise and all that.


Your CB is uses AM moulation.
50% of the 'power' goes into the carrier.
25% of the power goes into the upper sideband and the last 25% goes to the lower sideband. So, 75% of your power is not doing you any good now. Couple that into your usual crap CB antenna, and it is a wonder that you can talk more than 2 blocks. Best best, get a high gain antenna.

CB receicers are as wide as a barn door and selectivity suffers. Not much you can do there.

So what? Jacking up the power will gain you very little. (No pun, really) Really, it's not just a law, it's physics. Do the math, 75% oif what you 'add' is wasted right out of the chute.
Then that whole "invesrse aquare wave Law" thing kicks in again.


You want better 'talk power and range"?
Buy a SSB rig, 12 real watts out, a 12 to 15 dB gain in system efficacy due to the nature of the system and you get twice as many 'channels'. All legal. How cool is that?

Get a tech ham licensem and you can run 250 watts SSB on 10M, upgrade to General and you can run a full kilowatt.
UPgrade to Extra and you get to talk about your latest doctor visit....

(edit for more gooder speling)

[Radio guy]

You can increase the power slightly and make it sound a little louder but it will not make any magic increase in range. If the stock radio is scratchy and barely readable at some distance it might be a little easier to copy it at the same distance after the tuneup at best. You also need sufficient test equipment to perform the tune up making sure the output power is optimum for the amount of audio available to modulate the radio and to avoid spurious and harmonic output.

The difference in going from a stock 4w to maybe 6w after peaking means almost nothing to increasing distance, you need to make a substantial increase like at least 6dB (4 X) or 10dB (10X) which would be violating FCC rules. That's not a law but it can cost money if you blast through your neighbors TV and stereo and they start complaining to the FCC.

Its much easier to increase the range of a CB by raising the antenna and/or getting a bigger better antenna.
Radio Guy

[gary in ohio]

Do keep in mind you need to go 10x the power level to really make any noticeable difference. Any way you go your illegal. Also keep in mind
increasing your power doesnt allow you talk any further if the other end hasnt also incrased their power...

[klrvagabond]

Quick question: is the power limit on CB based on total output or ERP? I haven't messed with CB in forever.

[ace of shades]

So for my second post past my intro I will chime in on this subject. A little back ground - in the mid 90's when I was young, had a major disposable income, and all the time in the world (still in school) I did everything with a CB this side of getting my HAM lic *mistake*. I have done the very thing you want to do to your radio and agree completely with everyone else

1) as stated by yourself, and everyone else It's a crime punishable by the "FEDERAL" communications commission - a federal crime. I have watched good friends loose a lot of stuff and money because of this

2) The risk is not worth the reward. Ignoring the crime side of it, you "over clock" your radio you just paid $900 for, you turn it on you will be able to piss your neighbors off so well, everything you say goes into EVERYTHING (tv's, radios, phones anything with a speaker) and then it starts getting warm, then it starts smoking and you're out a good hunk of change because you OVER over clocked it

If you really want to reach out farther Upper and Lower sidebands are good, HAM is better. If you insist on doing the "tuning" method I would suggest a SWR and get it down to .5 or so and find a linear amp. They are available but they are NOT LEGAL. Basically anything you do to a transmitting device to up the power is flat ass illegal

CB Q and A http://www.nat-com.org/art02.htm

a couple of highlights -

Q: Are CB linear amplifiers legal in Kentucky? I got an electrical supply
catalog from Kentucky that has CB amps in it... "SWAMP THING", Baton Rouge,
LA.

A: No, CB transmit linear amps ("linears" aren't legal in Kentucky, and
since it's an FCC federal regulation, they ain't legal in "them" 49 other
states either. ANY type of transmit amplifier that will work on a CB radio
can not be legally sold or used in the United States. I guess that hasn't
stopped the catalog place in Kentucky...yet.

Q: I know someone who has a Ham license and he also has a linear amp on
his 40 channel CB radio. He said he could use it because has an Amateur
license. Is this true?...."CHICKENFOOT" Coatsville, PA.

A: Tell him to put down that crack pipe and brush up on the FCC rules.
There is no license you can have, get or buy in the USA that allows you
to run more than the regular 4 watts AM, 12 watts P.E.P. SSB on CB radio
channels.

[crypto]

I know, I know the FCC Nazi Ninja's will come cart me away if I tune my radio, blah blah blah. Has anyone here ever done one on a Cobra 29LTD Classic? If so do you have a tutorial, or can walk me through doing it? I want to increase my power due to the topography of my area (colorado rockies)

If you want to tune your CB within legal limits, you need to get a SWR meter, plug it inline with your antenna, and then adjust your antenna length (Firesticks have a tuning section in the end, whips usually have a threaded base with a set screw) until your SWR is as close to 1.0 as possible.

Thats all there is to tuning a radio antenna.

Now, if what you meant is "how do I increase power beyond FCC limits", then you can fuck off. People like you are part of the problem.

[aa1pr]

I know, I know the FCC Nazi Ninja's will come cart me away if I tune my radio, blah blah blah. Has anyone here ever done one on a Cobra 29LTD Classic? If so do you have a tutorial, or can walk me through doing it? I want to increase my power due to the topography of my area (colorado rockies)

If you want to tune your CB within legal limits, you need to get a SWR meter, plug it inline with your antenna, and then adjust your antenna length (Firesticks have a tuning section in the end, whips usually have a threaded base with a set screw) until your SWR is as close to 1.0 as possible.

Thats all there is to tuning a radio antenna.

Now, if what you meant is "how do I increase power beyond FCC limits", then you can fuck off. People like you are part of the problem.

You always tune into a dummy load, access to a spectrum analyzer would be best as I have witnessed many of these modded CB's bleeding over onto 10m, not because of any power increases, but because they are so damn far out of specs leave the thing alone I have to say, or look for an older Ranger 2950/2970 & have go...get your license and run some real power on the real bands

[crypto]

Well, the dummy load is a good idea if you're getting into the CB, but I think by the time you do that you've already defeated the type certification for the radio and made it illegal to run on CB. A dummy load wont help you impedance match the antenna, which is where most of the power loss comes from anyway. That has to be done with a SWR meter and the real antenna, as you know.

[klrvagabond]

Yeah, I really don't get it. A Tech license takes maybe about 30 minutes of studying and $10 or $15, and it allows for much better communications. Why bother with CB, even if the FCC wasn't an issue? It's inferior technology. Hell, a tech with ~$100 worth of gear can talk to satellites.

[aus.templar]

I got my mobile phone, when that stops working I've got some tin cans and some string... I really should at least get a couple of those 5km range two ways just incase.

[ZombieSoldier01]

I got my mobile phone, when that stops working I've got some tin cans and some string... I really should at least get a couple of those 5km range two ways just incase.

The problem is I live in Colorado Springs, Colorado which is at the base of the Rocky Mountains. Elevation is roughly 6500 feet. I travel 10 miles from my house into the mountains and I pass 3 mountains (one of which is Pikes Peak), which are 10,000 feet to just under 15,000 feet elevation at its peaks and below 7,000 at its valleys. There is no cell phone reception there, and thankfully the Forest service uses CB's and if asked, which I have, they will give you the channel they are on for emergency uses.

[klrvagabond]

Well, I can see the case for owning a CB under those circumstances, but additional output power will do almost nothing for you in terms of punching out over the terrain. You could probably run 10x the power or more and only get a marginal increase in signal scatter. Power and antenna efficiency help with direct line of sight and bounce transmission, but that doesn't seem to be the problem where you are.

[JohnE]

I find it hard to believe that a Federal Govt. agency relies on CB radio for any type of serious communications, especially any sort of emergency communications.

The terrain described is the absolute worst type for any sort of decent AM radio propagation.

Is there any chance that whoever told you the Forest Service was using CB's was incorrect?

[ZombieSoldier01]

I find it hard to believe that a Federal Govt. agency relies on CB radio for any type of serious communications, especially any sort of emergency communications.

The terrain described is the absolute worst type for any sort of decent AM radio propagation.

Is there any chance that whoever told you the Forest Service was using CB's was incorrect?

nope they are running cobra 29's like what i have in their trucks. they had me set mine to their station and do a test transmission, and it worked.

[crypto]

Many law enforcement agencies monitor CB for emergency assistance requests (pro-tip: its channel 9).


CB does have some technical benefits over the VHF/UHF bands you have access to with a technician class amateur license: Longer range, and the possibility of ionosphere propagation are the big ones.

On the downside, you can't use a repeater on CB, which is where other bands shine. Repeaters are a big force multiplier, specially when there are terrain features present: You put the repeater on top of the mountain, and anyone with line of sight to the mountain can talk to each other.

I'd be shocked if CB was the /only/ band the Forest Service had available to them, since typically long-range emergency comms are done with a low-band business-class radio and a repeater.

[FireEagle1071ad]

I find it hard to believe that a Federal Govt. agency relies on CB radio for any type of serious communications, especially any sort of emergency communications.

The terrain described is the absolute worst type for any sort of decent AM radio propagation.

Is there any chance that whoever told you the Forest Service was using CB's was incorrect?

A fair number of governmental entities in Colorado have been known to have a CB Base Station (or mobile plugged into a converter) laying around their office, some (usually county and local entities) have been known to either on an individual (as in indivual LEO or Ranger) to keep CB mobile units in their vehicles. The main reason for this is to monitor and help stranded 4 wheelers (I don't mean quads, I mean like modded jeeps, Pick-ups, even stock 4x4s, etc), its also not uncommon for avid and properly minded 4 wheelers to come upon individuals in need of help, and the only way to call out for help is the CB the 4 wheeler has. I was under the impression that most agencies who had CB radios monitor channel 9, but I could be wrong.

Anyways, the best thing to do is to mount the CB antenna properly, get the proper antenna for your your needs, and then tune the radio using an SWR meter.

[JohnE]

Well I believe you but I sure hope they don't rely on a CB in any sort of an emergency.

For monitoring sure but given the extreme limitations of the band, it's an odd choice to use for any serious communications.

Having said all that, it's still illegal to modify your radio...

[klrvagabond]

CB does have some technical benefits over the VHF/UHF bands you have access to with a technician class amateur license: Longer range, and the possibility of ionosphere propagation are the big ones.

Just FYI: Tech gets some 10m privs now as well, which is pretty close to CB (11m)...but you can run 200W PEP.

[CitizenZ]

You can slaughter the output of a "tuned" CB29 by using a high gain antenna and a ssb CB radio like the CB148 or Galaxy 959.

Any money spent on "tuning" or "amps" would be much better spent on bigger antennas and towers. It will talk and listen farther than a "tuned" radio and linear amps. Legally, for less power and money.

[FireEagle1071ad]

Well I believe you but I sure hope they don't rely on a CB in any sort of an emergency.

For monitoring sure but given the extreme limitations of the band, it's an odd choice to use for any serious communications.

Having said all that, it's still illegal to modify your radio...

I believe that the USFS is running on VHF, I know that VHF is pretty good out here if you can get the right mountain top (and when your the .gov and own most if not all the 14'ers in the state ), you can get some pretty good runs. A local HAM club has a 2M repeater up on I want to say Horsetooth Reservoir (mtn?) and they can talk with anyone from Denver to Cheyenne. With that said they are very selective of who uses their repeater and pretty much you need to be a member of the club or a visiting ham with approval.