Custom CB Radios

04/26/2026

Modulation: the hard truth…

On CB (Citizens Band) radios, “modulation” simply means how your voice (audio) is impressed onto the radio carrier. The “truth” is mostly about limits, tradeoffs, and a lot of myths.

1) What modulation is on CB
CB uses two main voice modes:
- **AM (Amplitude Modulation):** Your voice changes the *amplitude* (strength) of the carrier.
- **SSB (Single Sideband: USB/LSB):** A form of AM where the carrier and one sideband are suppressed; your voice becomes a shifted “sideband” signal. It’s more spectrum/power efficient.

(Some CBs also support **FM** your voice changes the *frequency*.)

2) “More modulation” is not always better
People often chase “100% modulation” (AM) or “swing” because it sounds louder. Reality:
- **AM:** Clean modulation tops out around **100%**.
- **Under-modulated**: sounds quiet/weak.
- **Over-modulated (>100%)**: causes **splatter/distortion**, makes you harder to understand, and interferes with adjacent channels.
- **SSB:** There isn’t a neat “100%” target. The goal is strong audio **without ALC/limiter abuse** and without flat-topping/clipping.

Loud ≠ clear. Intelligibility wins.

3) The common myths (and what’s true)
Myth: “Turning up the mic gain all the way gives the best range.”
**Truth:** Too much mic gain causes distortion/overmodulation. Range and readability usually worsen because the receiver can’t decode muddy audio effectively. Set the radio mic gain to a level that's comfortable for the people you're talking to.

Myth: “A ‘power mic’ adds watts.”
**Truth:** It doesn’t add transmitter RF power; it boosts audio drive. Used carefully, it can help, but it can also overdrive the radio and create splatter.

Myth: “More swing means more talk power.”
**Truth:** AM “swing” (PEP increase on voice peaks) can be normal, but chasing big swing often means:
- reduced carrier too far (harder to tune/less consistent),
- heavy distortion,
- and more interference.
Clean audio at normal power often outperforms distorted “big swing.”

Myth: “Clipping the limiter makes you louder and better.”
**Truth:** Clipping can make you seem louder up close, but it usually increases distortion and adjacent-channel interference. Many stations will hear you as harsh and wide.

4) Legal/technical reality (U.S. regulations)
- **AM CB:** 4 watts carrier (FCC limit).
- **SSB CB:** 12 watts PEP.

5) What good modulation looks like (practical)
For **AM**:
- Aim for clean audio that peaks near 100% without splatter.
- If you have a modulation meter/scope: avoid flat-topping and negative peak cutoff.
- Set mic gain so normal speech is strong; shouting shouldn’t make it distort. However, there is no reason to shout.

For **SSB**:
- Set mic gain so your voice drives the radio strongly but doesn’t constantly slam the ALC.
- Speak normally, closer to the mic; consistent mic technique matters more than raw gain.

6) The biggest factor people ignore: antenna system
If you want to be heard:
- A properly tuned antenna (low SWR, good ground plane, good coax, good mounting) usually helps far more than audio mods.
- Poor antennas waste power and create problems that no “modulation tweak” fixes.

7) How to check if your modulation is clean
- Ask multiple stations for **audio reports** (not just one).
- Monitor yourself on another receiver at a safe distance (or use a dummy load + monitor setup).
- Watch for complaints like “you’re wide,” “splattering,” “garbled,” “harsh,” “sounds like you’re in a tunnel.”
In conclusion, you can make a radio loud and seem to be doing a great job, but the fact is that most of the time you're wasting power and creating unnecessary heat that causes the radio to fail prematurely, and causes splatter and does not give you any more range, or if it does, you are sacrificing sound quality for what you're gaining in range. I suggest you do some real-world testing and make up your own mind as to what kind of radio station you want to run.
CBR
Custom CB Radios

From radios to repairs — everything you need in one place

04/01/2026

An old project I did.

6 new items · Memory by Doug Mullens

03/27/2026

Can you find the problem?
This is a Galaxy 929 just for information.

03/25/2026

Need a radio? We have them...
Contact us for your radio and accessory needs.
We also repair radios that others can't.
Call us at: 812-420-1226

www.customcbradios.com

03/21/2026

Amazing Deal while supply lasts...
Open Box President McKinley SSB CB Radio.

03/19/2026

Special Deal!
President Randy Hand Held CB Radio Sale.
$115.00 Get them while they last.

Explore the unique features of the President Randy CB Radio for seamless communication on the go. Perfect for all your needs!

03/16/2026

I am offering a brand new President Lincoln II + radio for sale. This unit has undergone conversion and remains in its original modified state otherwise. For an additional fee, I can fully configure the radio to your specifications. The sale price is $325.00 for the converted unit, or $365.00 for a fully set up and ready-to-use device.
https://customcbradios.com/product/president-lincoln-ii-10-meter-radio/

03/12/2026

Got a few radios in today...

03/05/2026

Are you being deceived by rhetoric?

I watch many videos and listen to many comments about how to tune and run your radio.
What is good and what is bad? If you do this mod, you're going to damage your radio, and it will sound like crap. Well, that’s fine and good except that a lot of the people don’t even know what the parts they are talking about are, let alone how they will damage your radio.

Let me give you an example, the coils in the back of your radio that many are saying are not to be touched are not coils, they are inductors (not coils), and while they are turned to the diameter to have a certain inductance, spreading them a little fine-tunes the circuit. It does not damage the radio; in fact, on some radios, you see they are bent from the factory for proper adjustment. They replaced the adjustable inductors that used to be in radios that you could adjust. (cheaper cost) Remember your dealing with parts that have a +/- 20% tolerance, so each radio needs to be fine-tuned to achieve maximum performance.

Let's talk about tuning your radio and increasing the modulation on it. The myth: if you increase the modulation, you will sound like crap, and the signal will become distorted, when in reality you still have total control over it on the front of your radio with the mic gain control, so you lose nothing and gain louder clear and cleaner modulation if you set the control correctly. (Note, every k**b doesn’t have to be all the way to the right)

So, can you mess up your radio trying to do some weird mods to it? Absolutely, that’s why there are shops that do this work daily and have experience and the proper equipment to handle the job for you, the thing you have to do is to find a shop that is doing work correctly and not trying to sell you a bunch of snake oil, or telling you that your tune will consist of tuning your radio to stock when in fact it come stock from the factory! The just doesn’t make sense to me, and it shouldn’t make sense to you either.

Another issue, the new surface mount radio can’t be modified, well, they most certainly can be, and I do them daily, the solution is NOT in the service menu, it takes hardware mods to give you a real improvement to the radio, however I don’t recommend that you try and do mods to SMT boards unless you have the knowledge and experience to do so or you may end up with a paper weight instead of a radio.

If you're running a President radio, I highly recommend a Digimike as the microphone to run on it. This mic will enhance the sound and make the radio have a smoother sound, and is designed for the radio. I do not recommend running a Astatic 636 or SR 198 type of microphone on these radios, the sound will not be as good and many cause damage to the radio when trying to wire the microphone along with the radio sometimes changing channels when you key the mike as it uses the voltage from the keying circuit to change the channel as well as key the radio depending on the pull down of the voltage on the circuit.

In the end, pay attention to what you're being sold on and don’t just blindly believe everything you see on YouTube and in the FB groups, as many are not properly trained and are just selling you on their fast-jack tune to get your money, and it’s not doing you justice at all

CBR
Custom CB Radios

03/01/2026

Digital or analog, what is best for you?

We are all used to setting the k**bs and moving on, but today, manufacturers are moving to a different way of manufacturing radios and are moving more to incorporating menus into the radios.

Why is this happening?
There are a couple of reasons. Firstly, it’s more cost-effective. With the advent of microprocessors that can handle multiple functions, a simple operational amplifier can perform tasks that used to require analog switches. This change reduces both the cost of production and the labor needed to build radios, allowing for more features than ever before. Secondly, space is becoming increasingly tight in modern vehicles. There often isn’t enough room for traditional radios, and in new trucks, manufacturers are designing specific, smaller spaces for radios. In fact, the designated space has become so limited that older Galaxy and Connex-style radios no longer fit.

What does this mean for you and me?
It’s going to be a learning curve but in the end you are going to be happy with the results you get, once you get used to the menus and how to set up the radio, it will be normal for you just as the way you are used to now, and some of the old problems you have had in the past will for the most part will be gone like, cold solder joints, broken wires and cracked circuit boards as the new boards are far more resilient and heaver built, (no more board flexing and sagging) Surface mount parts are soldered flat down to the board and are not prone to vibration problem like the through hole built radios are, this will make the radio last much longer than you are used to, in fact you will most likely get tired of the radio before you have any problems with it.

You can’t tune a new radio.
Well, that’s just not true, as there are mods that will give your radio a nice increase; they are new, and some shops don’t have or understand the mods yet, so that’s a great reason to buy from a shop that is familiar with the newer design radios. Here's a little secret: the mods you need are not in the service menu. As a dealer that services a lot of these radios and does the warranty work for President, I can say that I see a lot of radios that are getting returned because people are getting into the service menu and messing up the radio. Service tidbit: resetting the radio will NOT reset the service menu of the radio.

At the end of the day, change is inevitable. I suggest that you take the time to look at the new radios and give them a chance to see what they truly have to offer and see if they won't do the job for you.

CBR
Custom CB Radios

02/27/2026

For all you guys that are running Cobra 29 LTD radios, I want to talk to you about a new radio from President that is far better than Cobra's latest fiasco of a radio.
It’s called the President JFKIII FCC 40-channel CB Radio. This radio is loaded with cool features and has more talk power than the cobra and the build quality is far better.
Some of the features of this cool radio are: Front-firing speaker, so you can hear without an external speaker, a large 7 color LCD that is easy to see and read, need to check you SWR, this radio has an automatic SWR function built in, for you dump truck drivers it features a 2 channel programmable switch so you can set and forget it when you need to go into the quarry just flip the switch and your there, built in noise reduction to help with the noise you deal with and finely a USB port, charge your phone or power any accessory right from your radio.
Pair this radio with the President Digimike, and you have a great-sounding and long-lasting radio that will serve you for a long time.
For more information, click the link below.

Size : 7.28" (W) x 6.89" (D) x 2.24" (H) OEM Truck Size : Power Supply : 12 V AM : FM : Memory : 5 Channel Scan : Scan Skip : SWR Meter : Filter ANL

02/22/2026

Do you get what you're paying for?
Well, that’s an interesting question for sure, as a lot of so-called mods and tunes are not what they seem. Do you get what you are paying for, or even better, do you know what you want, and are you getting that from the shop you are giving your money to?
We have to start with do you really know what you want, while at first though you may think you know what you want but are you able to get the idea you have across to the shop your dealing with, are they interested in what you want and are they willing to talk to you about it pros and cons of what you want to make sure you will be happy in the end.
Many shops will tell you what you need without listening to what you are trying to accomplish, because they just want to push their mods they use daily and that’s about it, the problem with that is you may end up with a new radio that you don’t like because of the way it preforms and now your going to have to find someone else or get rid of the radio for a loss.
This is especially true of the high-volume stores; they may offer the service, but most of the time are vague about just what they are doing to your new radio. The other issue is shops that try to sell you absorbent mods that are expensive, but in the end ,did you get much for your money other than promises, did the mods make a difference or did you just donate to their cause?
My suggestion to you is to think about what you want and then contact a shop and covey exactly what you are looking for and see if they seem to be interested in do that for you, don’t spend a lot of money on fancy mods that do nothing for you but take your money and most importantly, don’t believe everything you see on u-tube or what many post online on some of the forums. DO YOUR RESEARCH and get what you pay for.
CBR
Custom CB Radios