I know nothing about CB Radios - Well, almost nothing...

This may sound oversimplified, but the most sophisticated radios available out there will be for naught if they don't get fed into an efficient antenna system. And by "antenna system", I mean everything from the first coax connector that plugs into the back of your radio out to the antenna itself, including any feedlines, tuning devices, mounts, harnesses, coax couplers, even the vehicle's body itself, and ultimately the ground over which you drive, although there isn't much you can do to modify that last item.

Everything else being equal, a longer antenna is better than a shorter one. A full size antenna for CB is around 102-108 inches in length; anything shorter than that is a compromise. Sometimes we've got to live with those compromises because of restrictions by statute (vehicle height), practical considerations (overpasses, petroleum loading racks, shop doors), company policy (no holes in the truck, nothing permanently mounted on the truck, no antennas besides what's provided by the truck manufacturer), and stuff like that.

Ideally, we'd all drive vehicles with flat (or slightly curved) bare, tarnish-proof metal roofs that extended at least 10 feet in all directions from the center, where we'd mount our ~105-inch whip though a hole that would let us make the coax connection inside the cab where it would stay dry, and allow us to make a short, tidy run to the radio, then conceal it neatly behind a headliner that we could remove with a moment's notice to check things.

I didn't just fall off the turnip truck, however; I've been transmitting signals into the ether since 1962 with my first home made transmitter, and have gotten used to practical limits and how to work with them.

Remember as you shop for antennas that loading coils used to shorten antennas physically do not radiate, so they essentially waste space. The longer the whip, the less coil is needed. And the more flat (or equivalent) metal area that you can arrange to meet at the precise point where your coax attaches to the antenna, the more efficiently your antenna will function.

For power levels under 150 watts, the coax that comes with most antennas is OK. There is no magic length for coax if you're feeding just a single antenna. If you're going to feed paired antennas, you'll have to use a special harness made of special coax. But for a single antenna, the right length is the distance from the radio to the antenna.

I've been using a simple Cobra 25 to a 102" whip with a potbelly spring on the side of my minivan for the last 5 years. It'll talk about 8-10 miles reliably to another mobile that's set up correctly unless we're being blanketed by skip. I can talk to my legal base station from about 15 miles out under the same conditions.

Put your money into the antenna system first. If that's optimized, you can do fine with a Uniden Pro 520XL. I'd say a 510, but the RF Gain control is nice to have if you're surrounded by Kilowatt Kings on the road.

As for "noise toys", if you want to actually get your voice understood by someone and get information across, don't try to sound like a Cylon or a braying donkey. If you feel like you need to annoy folks, I'm sure there will be other posts by folks who can identify specific noise toys for you. For me, audio distortion is just that -- distortion. I do my best to make sure that my audio is as clean as it can be, so that I (and my customers' radios) can be understood until the last whisper of their signal fades into the cosmic background noise.......or some guy saying, "I ain't got no panties on."


73,
Handlebar

 

You can NOT know less than I do. I have an 11-year-old Cobra 29. Never been on a bench....nothing. So a day or so ago, after I release the key on the mic, the meter "sticks", as if the thing is still keyed on (which it may have been). I can strike the mic with my open palm and it clears. So....what do I do? Grab a screwdriver. My solution to everything. Either that, or a 4-pound hammer.

I take the back off the mic, knowing full well I'll find nothing I can name, find, or fix. But I can fiddle. And so I do, for about a minute. Takes longer than that to put the stupid back on the mic again.

But it's working. Have no clue what I did. Zero. Zilch. Nada. However, I strongly suspect I may be in the market for a new radio soon.

 

48P,
It's possible that the needle movement just got mechanically stuck; it happens. It would be neat to know if the TX light was on, too, or if it was just the needle's position that had you concerned. If it *was* just the needle, and since you can fiddle, you can pick up a new meter online for ~$10; a couple of wires for the meter, a couple of screws, move the light, et voilà!
The part on most radios that gets the most wear is the mic's cord, followed by the volume control, then the push-to-talk button, more or less. If your mic stays keyed, suspect the cord, as long as the button came all the way back out when you let go. Wiggle the cord around where it enters the mic, and again where it enters the plug on the radio. If you grab ahold of the cord and sorta turn the cord gently like a crank while you watch the front of the radio, you may see it start to transmit as you get one end or the other to a certain point in the unholy manipulation.
At that point, if you feel comfy with soldering, cut off that end a couple of inches from the end so you can see the colors still, strip the little wires inside the new fresh end, and *then* open the connector or mic's head and find where each of those colored wires goes and replace them, one at a time, like spark plug wires.
Or go to Radio Shack ("Radio Shack: You've got questions, we've got blank stares!") or Amazon or someplace and pick up a handy replacement mic for like $12.95 and just put it on. Sometimes it's easier to just pay and get back on the air, unless you feel like it's a good time to get some learning time in.
If that's the only thing that's going wrong with your radio, and if it's a "daily user" for you, then there's really nothing that wears out in them. If it had been sitting on a shelf for 20 years, you'd be well advised to replace the electrolytic capacitors before powering it up. But the only things that move are the mic, the meter, and the controls behind the knobs. Eventually the controls may develop some noise, and a shot of DeOxit or other contact cleaner may fix them; if not, getting the front panel off can be a bit of a project. Otherwise, I personally wouldn't throw away a '29 for a sticky meter (or bad mic cord). I've got a couple here from the early 90s that still run like new (or they do now, after I un-butchered them).
Most stuff really is easy, if you take it in little chunks.
Hope that helps,
73,
Handlebar
diddly dahdidah
dit dit

 

I'm a very, very light CB user. I listen far more than I speak, and it's pretty selective even then.

The push-to-talk button was what I was first suspecting, but it seemed fine. I want to say the TX light stayed on as well. Whatever I managed to not screw up, it seems to be working once again. But I'm not afraid to solder....I've replaced more than one plug on a cooler or five. And I was actually halfway planning to just try another mic if all else failed.

It did sit for over 3 years when I was off the road, though, so using some contact cleaner might help as well.

But it still seems to be a good solid radio, though the meter light has long since failed. I suppose I could replace that if I had a weekend!

 

Hi Joe,

You need to figure out what you want to do with your CB. I'm going on the assumption that you are wanting to talk with whoever is out there.

Distance: Most of the time, you are talking less than a mile. Traffic problems, "bear reports", and the like are nice to know a few miles ahead of time, but your typical source is the guy passing you going the opposite direction. If you just want to "ragchew" (long chat) with someone going your way, you'll likely remain fairly close to each other. Regardless, the other guy is probably running a 4 watt stock CB, so you cranking out 100 watts isn't going to let you hear him any better.

A good antenna system will improve your reception just as well as your transmission. Handlebar has some good comments regarding antennas, above.

Radio tune-up, aka a "tweak and peak", "fluff and buff", or the like: You have to be VERY careful with this. There are a few good radio techs out there who can make a radio stand up and sing.

Power mods: Beware the radio guy who says he can double your output power with just a screwdriver. Yes, you can make your CB read double the power on a power meter, but two things will happen... your signal will sound like crap, and your "final" (power output transistor) will let out its magic smoke before long. What is happening is the final is being overdriven, causing spatter, and it's using more power than it's designed to use. Basically, it'll fry itself.

Side note: You'll hear people talk about "swing". Swing is a byproduct of modulating the carrier. A properly tuned CB will put out 4 watts dead key, and just under 8 watts peak when in use. Run far away from the guy who says he can set your radio for 2 watts dead key and 12 watts "swing". You're doing something like 300% modulation, putting 3-4 watts (if you're lucky) on your channel, and the rest splattered all over the place. Yes, you will actually have LESS "talk power" on channel.

Sound effects: "Roger beeps", echo boxes, and all that crap is a sign you're a "n00b". Use those, and you'll find people are less willing to talk to you. On the other hand, a properly set up speech processor driving a radio to 90% modulation will give you a signal that's really pleasant to listen to. (That's what the AM broadcasters do.) Undermodulation is what makes a person sound weak on the air, and a properly adjusted power mike will help a lot.

Yes, I did use the phrase "properly adjusted" quite a few times. That's what makes a good radio tech a good radio tech.

 

Well, that's cool. Good chance to put in a lamp that'll last forever by using an LED then. A chance to use one of a color of your choice. Use some sandpaper to "frost" the translucent surface of the LED to diffuse the light, so it doesn't work like a spotlight and light up just one little part of the meter's scale. Cut off the existing bulb's leads close to the bulb so you don't have to go fishing around to figure out where to attach them. Solder a resistor of around 1200 to 2200 ohms, depending upon how bright you want the light to be (bigger number = higher resistance = dimmer light) onto either leg of the LED. Slide some heatshrink, if you've got it, over the resistor and up to the base of the LED. While you have it out, slide enough heatshrink over both of the original leads to cover what will be the solder joint from the resistor's only remaining end and one original lead, and a piece for the other original lead for the other LED leg.
The old bulb didn't care which way it "pointed"; it was just a dumb bulb, and would even have worked with a.c. The LED, though, is a diode, and will only pass current in one direction.
One leg is either longer, or has a flat ground on its base, or is otherwise identified as its cathode. That end will have to go towards the ground lead, which will be one of the two original bulb's leads. The other leg, the anode, will get the + voltage. If you've got a DC voltmeter, the textbook way to find out which is right is to carefully isolate everything from watchbands, rings, stray tools, drooling kids, gum wrappers, pools of mercury, and Cesium-137 sources. Or just tape the stripped original leads down to something that will keep them in place while you test and then solder them. The frame of the radio would be a *bad* place to tape them, unless you cantilever them so they stick out a couple of inches like little wilting diving boards.
Power up the radio, put the black meter lead on one of the coil cans inside the radio (the chassis may not be at DC ground) and put the red meter lead on the original leads, one at a time. Only one should show about 13 volts; the other should show 0. Mark the one that has voltage on it, power down the radio, and disconnect the power.
You'll want to figure out for yourself if you want to mount the new lamp in the meter housing while the meter is still out of the radio, or after you put the meter in; also whether to solder the LED to its wiring after physically mounting the LED so it holds itself in place, or if you'd rather hook it up outside the radio, then snake it in.
When you get to where you're ready to solder it on, first find the pieces of heatshrink that you'd put on the original leads earlier, because if you're like me, 3 or 4 things have interrupted you, and the radio has been lifted and tipped upside down a couple of times, and they've fallen off the leads. The cat may be batting one around on the floor, thinking it's a bored bug (my cat's not very smart).
Sigh, then put on new pieces of heatshrink, or resign yourself to using electrical tape. Make note to self: next time, get smarter cat.
When you choose an LED, try to remember that, even though blue lighting seems to be all the rage, it destroys your night vision. (hint: google "vision purple")
And I usually go for a brightness level that will be no brighter than what I'll want something to be when the car is dark; I don't want the CB to be the brightest thing in the car, and if I really *need* to see the meter, I'll be stopped at the side of the road with the time to stare at it for awhile anyway. I've got red or amber lighting on all my commo gear in Ye Olde Porcupine Van, and it's all pretty dim, much like its driver.
For contact cleaner, remember to have the radio powered off when you use it. Even 97% isopropyl alcohol will conduct low voltage. If you use alcohol, everything that isn't alcohol is water, so 70% is a poor choice for everything but cleaning grease off the cases.
I use Caig De-Oxit D5 spray and D100 for controls. http://store.caig.com/s.nl/it.A/id.2527/.f has a 2 ml tube of the D100 for dripping or wiping onto surfaces you can actually reach, and a little 15 ml spray can with a straw for spraying into controls. That's the same stuff, in smaller quantities, as what I use in the shop for everything except tube gear, which gets some of their other products for high temps. I actually carry the same 15 ml can in my bass gig bag for on-site amp & cord fixes at band gigs.
Sorry that was so long. I've been told that when someone asks me what time it is, I tell them how to build a clock, how to set it, maintain it, authenticate it, and publish its history.
73,
Handlebar

 

Cuppa,
MsJamie is probably the best mind you'll see posting on this board. You can take what he posts to the bank, as they used to say. As you look through the forum, you'll see all kinds of info, and lots of ideas to which he alluded; fortunately he has also warned you of their pitfalls.
It's hard to overcome the principles of physics that govern radio waves. When someone approaches you with a smile and a secret gadget for a mere $59.95 that'll cure all your radio ills, count the spoons and bid your farewell.
73,
Handlebar

 

Is that like the stuff at the auto parts store with the word "Miracle" in the title??

 

I know nothing about CB Radios - Well, almost nothing...

you wiil find most of the people on this site are in the same boat..

go here..

www.cbradioforum.com