Code plug is a term you hear tossed around a lot in the amateur radio DMR community. It’s almost like it is a mystical thing that can only be shared and not created. But alas, somebody somewhere created that “code plug” that is being used in that DMR radio in your hand. The code plug is just a term used to describe the set of programming instructions that are sent to your radio when you use the software to program it.

The term code plug come about many years ago in the commercial two-way radio industry. Before radios used microprocessors to control functions of the radio, crystals were used to control the frequencies used. They may have also used internal jumpers to control other options. Later on, the jumpers were moved to a jack on the back of the radio. Then plugs were configured with wire jumpers that would plug into the jack to enable certain functions such as CTCSS encode and decode. These were the original code plug. As time progressed, things became controlled by a “computer” inside of the radio. Software was then used on a PC to program the radios. Although there is technically no code plug, the term stuck.

For many years, there were just a few basic things you would program a channel with in your radio. These would normally include the frequency, offset, CTCSS tone, and the channel name. The software may also allow you to change options such as scan, squelch, and other options on the radio.
With the advent of digital radio, those have changed. With DMR, channel information will include the operating frequency, time slot, color code, and talk group. And unlike analog where you usually had a different frequency for each channel, with DMR you may have 10 channels, all with the same frequency and color code, but the time slot and talk group will be different. Then you have ‘zones” that must be entered too!

In amateur radio, we have had the luxury of programming our radio the way we want it. You may have 3 members of a club with identical radios, but they would each program their radios different, to suit their own personal needs. The commercial world is a bit different. A radio shop may program a fleet of radios for a business or public service, but they would basically be clones of each other. This makes it easier for the end users of those radios to operate them if they move between vehicles, or if they use a particular “channel” for a particular department.

Sharing code plugs helps to get your fellow ham on the air, but some problems may arise as well. The program that is shared may still include your DMR ID if it is not changed or deleted before sharing. Also if you are sharing it with another amateur a county or two away, some of the repeater info you have in there may not be beneficial to them if they aren’t normally in that area. And the “Chinese” radios that many of us are using can also be finicky when it comes to writing software and instructions to them. We as hams normally help another ham out. That is one of the many great aspects about the amateur radio community.


When you first sit down and look at a code plug, it can seem a bit daunting at first. To complicate matters, some of the programming software isn’t too clear on some functions. The software may not allow you to “copy and paste” therefore some of the same information such as frequency may have to be re-entered with each new channel. There is a piece of software by N0GSG called contact manager. If you do not have this, I would highly recommend you download it. I will share the link at the end of this post. Although it does not write the software to your radio, it can make programming easier, and allow you to exchange code plugs between different radios.

There are a few basics to do when creating a code plug. First be sure you read your radio, and save what it read to your PC. Although this is a blank file, it may be able to save you in the event something gets corrupted later. Be sure you have your own personal DMR ID programmed in the radio. Many radios will only allow one ID to be entered. Some may allow multiple ID’s and a few will even allow you to enter a unique ID with every channel. Next, make sure you have your contacts loaded to the radio. This is a list of all of the ID’s that you may want to contact. This list also includes all of the talk groups that you may want to talk on. On DMR, without keying up a talk group, you probably aren’t going anywhere. Now you start programming your channels. Each radio model will be a bit different. Channel information will include the operating frequency, RF power, time slot, color code, and talk group. If you are programming several channels that will use the same repeater, frequency and color code will remain the same on those channels. Some other information such and scan options and receive groups may be programmed for each channel as well. Zones will be the next item to program. A zone is just a group of channels put together. You may program a zone for each repeater, or for each town you are in. Zones may include both digital and analog channels as well. After all of this is done, you would normally write this to the radio, then you are ready to operate. Remember, each model radio behaves differently. Some options such as audio and mic gain may need to be adjusted as well.

For the N0GSG contact manager, go here:
http://n0gsg.com/contact-manager/