Should you get a peak and tune


When you purchase a stock CB radio from a CB shop most of them will offer to do a “Peak and Tune” for a extra fee. But what is a “Peak and Tune” and do you actually need to have it done?

In general a “Peak and Tune” means the following –

1) The radio shop performing the work will test your radio to make sure it is transmitting and receiving on frequency. If it is not they will make minor adjustments so that it is.

2) Most radios come from the factory with their modulation levels set around 70-80%. The shop will adjust your modulation level so that it is at 100%.

3) The shop will adjust your power output so that your radio has a legal 4 watt deadkey and is reaching an acceptable level of peak output with modulation.

4) The shop will tune your receiver for best performance so that signals sound natural and its sensitivity is acceptable.

Now many people will ask, why would I need to have this done on a brand new radio? Didn’t the factory make all these adjustments and set it up properly when they built it?

Well as with anything built in a factory even though they strive to have all the items come off the assembly line the same rarely are two items exactly alike. Small differences in manufacturing can mean that each radio will perform differently in the real world.

As for the factory tuning. Most factories test their radios to be on frequency and set the output wattage and modulation to be within the legal limits. But because they want to make sure all of their radios meet the FCC regulations they often tune them a little on the low side. They do this so that even if one of their radios happened to be a little more powerful than its brother from the same batch, it will still meet FCC regulations.

Having a CB radio that transmits under 4 watts with less than 100 % modulation is very important to a company trying to comply with FCC regulations, BUT it isn’t a very good thing for a customer who wants their CB radio to perform at it’s maximum potential.

Now most mass market CB radio buyers are buying a radio to talk to their 4×4 buddies, or maybe just to listen to trucker reports on the freeway and in their case a “Peak and Tune” is not really necessary. You don’t need to have turbo added to your car if you only drive in the slow lane, and there is no reason to have a peak and tune done if you only turn on your CB radio once a year to listen while on your annual road trip.

For most basic CB radio users a factory stock CB radio will perform well enough for them and they will never know the difference.

But if you’re reading this article and came to this website it’s likely you’re either a seasoned CB’er or someone who is looking to get more involved in the hobby and a peak and tune might be right for you. Before proceeding though make sure to ask yourself if a peak and tune is necessary for your needs and if you think spending the money will make your CB experience better.

There are some important things to think about before ever getting a peak and tune done.

#1) Most important – Is the shop you’ve chosen the best place to have your peak and tune done?

There are so many rip off artists out there these days and many CB shops will take your money and give you back a radio they didn’t do a thing to. Sad, but it happens. Possibly worse are the shops that try to do their version of a peak and tune without the proper equipment or knowledge. Often this involves removing key components of the radio (such as the modulation limiter) to make it sound loud. Many times these people will give you back a radio that is in worse shape than before they started their peak and tune. The radio may sound loud and do a lot of watts on their meter, but your voice will sound crackly and the radio itself may not last very long. Never trust a CB technician who says they are going to clip your modulation limiter, this is a hack way to do the job and any good tech will tell you the evils of doing so.

Another thing to beware of when looking for a shop to do a peak and tune is the meter that they use to show you the results. A watt meter can be adjusted internally to show whatever they want it to show. They may tune your CB radio and show you that it’s doing 50 watts output on “their” meter, but if you took it home and hooked it up to a real meter it may show it’s only doing 20 watts. It’s a bad trick, but many shops have “happy” meters.

The best way to find a good shop is to talk to people who have been around CB radios for a long time. Ask questions in CB radio forums and always make sure to ask the shop itself exactly what they plan to do to your radio. If all they will tell you is “Oh, we’ve got a way to make it sound awesome” don’t trust them. A good shop will tell you exactly what they will do to your radio. Would you trust a car mechanic who says “I can make this thing go fast but I can’t tell you what I’m going to do to it…’s a trade secret”.

#2) Once you find a good shop they may have multiple types of “Peak and Tune” options available. These may range from a basic tune (the steps mentioned above) or a more complex tune (which may involve replacing certain components).

There are many well known modifications that can be done to many radios. These modifications involve changing resistor values, adding resistors, or even replacing the stock final transistor with an aftermarket transistor.

These more complex tune ups are going to be more expensive but they can result in a radio with better receive, louder modulation and increased output wattage.

Once again you need to make sure you find a reputable shop to do these modifications and make sure to ask which modifications they will be doing.

Before spending the extra dough make sure to ask yourself – is the extra 20 watts I’ll see from this modification worth the extra $40 I’m going to be paying the shop?

#3) Buy your own SWR and wattage meter and do your own tests before taking it to the shop for a peak and tune.

The only way for you to tell how well your radio is performing is to test it out yourself on your own meter at home. Once you know what kind of numbers the radio is doing then you can take it in for a peak and tune. When you bring it back home you can then compare the final results with your original results and decide if the peak and tune really did what it was supposed to do.

#4) The most common reason people get a peak and tune is so their radio will have more output, but is this the smartest way to achieve your goals?

Your stock Cobra 29 LTD classic may have an peak output from the factory of around 12 watts if you’re lucky. After a very good tune from a shop that particular radio will max out around 25-30 watts.

You can have someone replace the finals and do some other modifications and maybe it will do 40-50 watts. But now you’re talking $50 or more just for the work done to the radio. If the original cost of the radio was $80 you’ve now invested $130 to have a radio that will do 40 watts. That may not be the smartest decision when there are dual final export radios available on the market for only $30-50 more that come factory designed to do 30 watts without any modifications.

There are also small amplifiers available for sale that can give you 100 watts of output for less than $60.

Yes both the export radios and amplifiers are illegal, but so is having a CB radio that will do more than 4 watts.

It’s easy to spend money at the CB shop, but you really need to stand back before buying and really ask yourself if you are spending your money in the smartest way possible.

A peak and tune can be an excellent decision if you choose the right shop, know what you would like them to do, and have a way to measure the quality of the work afterwards. As mentioned before, for many CB’ers a peak and tune won’t make any noticeable difference to them, while for other daily users it can make a world of difference. A properly set up CB radio can mean the difference between talking 2 miles and 10 miles. Just make sure you take the time to think through your decision before giving away your hard earned dough.