Narrow Band Emergency Messaging Software (NBEMS) is an Open Source software suite that allows amateur radio operators to reliably send and receive data using digital techniques. Its core component is the application fldigi (short for fast light digital).
The focus of this NBEMS-Local course is to allow the reader to gain proficiency in the use of the NBEMS applications using FM on the VHF and UHF bands for the purpose of participating in digital nets on those bands.
Here are links to other online introductory material for NBEMS:
Please keep in mind that the focus of NBEMS introductory materials that you will find elsewhere may well be different. fldigi and the other NBEMS applications are also widely used for these rather different purposes:
Operating on HF and seeking contacts with others may call for different operating styles than would likely be used on VHF/UHF for checking into a net, and especially to a busy net. Again, this document will focus on exploring skills and techniques that are used on VHF/UHF digital nets, though these skills and techniques are similar on HF digital nets.
The steps and exercises that follow will teach skills that will be useful to the NBEMS user: fldigi, flmsg, and flamp. Each step of this course will show, under Requirements, what is expected of you as you begin. In all cases, you will need a "computer", which can be a desktop PC, a laptop, or even a tablet or smartphone, but it must have fldigi installed and running. In most cases, you will need a transceiver. The transceiver can be anything from an inexpensive 2-meter "HT" (Handheld Transceiver) to a compact, mobile-style VHF/UHF rig to a sophisticated multiband desktop radio for worldwide communications.
In any case, there must be some way to get sound between the transceiver and your computer. If you have an "interface", which will include cables and probably some sort of box containing electronic components, and it works for you, you're set. Without an interface, your computer must somehow "hear" audio coming from your transceiver, and your transceiver must somehow "hear" audio coming from your computer. In later exercises, when you will be transmitting, your transceiver must somehow be placed into transmit mode at the proper time and return to receive mode at the proper time. With an HT, you can manage this, with some practice, by placing or holding the HT in a good spot next to your computer. However, this becomes more difficult when you are typing at the keyboard as you are transmitting, because you need to be typing, holding down the HT's PTT button, and maybe holding the HT near the computer's microphone all at the same time. You may be able to work this out, but you will have an easier time if you can obtain and use an interface.
When you install it, the fldigi application will create some subdirectories (folders) on your computer in which it stores and saves files that you can use. Some are templates that you will be using later in this course. Others will be created automatically as you use fldigi. In Windows, installing fldigi and other NBEMS apps will create folders in your User folder. The User folder is named with your login name on the computer you're using and contains your Documents folder and other files personal to you and is located at C:\\Users\your-account\. If you have already installed fldigi, you will see a folder named "fldigi.files" in your User folder. So, to keep things simple, I suggest creating a folder inside your User folder that is named "fldigi.learn" (see illustration at right).
It will be your personal workspace for this course, for storing files you create as you use fldigi and related programs and as you proceed through this course. For the rest of this course, we will refer to this folder as "your workspace folder", regardless of where you decide to put it.
If you use some sort of file-backup procedure on your computer, and that's a very good idea, ensure that the following folders are included in your backup:
This course uses the following method of describing software menus and other configuration choices. (This method describes the Windows interface. The choices available in other operating systems are, I hope, similar.)