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Introduction to digital modes via FLDigi for EmComm

Christian Helfrich K7XTN / WQYN614�Seattle Auxiliary Communication Service

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Fast, Light Digital (FLDigi)

  • FLDigi is the primary application in a software suite called the Narrow Band Emergency Messaging Software (NBEMS).

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  • NBEMS is open-source software for amateur radio operators to send and receive data using nearly any computer (Windows, Mac, and Linux) and any analog radio without dedicated digital infrastructure or specialized modem hardware.

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  • Anyone, including non-hams, can use the software to receive messages.

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We’ll use 2 apps from the NBEMS suite

  1. Fast Light Digital (FLDigi) - encodes and decodes digital radio transmissions; this is the backbone app

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  • Fast Light Messaging (FLMsg) - works in combination with FLDigi to send & receive formatted messages in common forms, like FEMA ICS-213 General Message

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Downloading FLDigi

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Download FLDigi & FLMsg for Windows

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Download FLDigi & FLMsg for Newer MacOS

  • MacOS 10.13 to MacOS 13.x

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Download FLDigi & FLMsg for Older MacOS

  • MacOS 10.12: Sierra-2016, OS X 10.11: El Capitan-2015, OS X 10.10: Yosemite-2014, OS X 10.9 Mavericks-2013, OS X 10.8 Mountain Lion-2012, and OS X 10.7 Lion-2011

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Download FLDigi & FLMsg for Linux

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If prior hyperlinks don’t work

Here’s the download page for FLDigi: https://sourceforge.net/projects/fldigi/files/fldigi/

This is what it looks like:

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If prior hyperlinks don’t work

Here’s the download page for FLMsg: https://sourceforge.net/projects/fldigi/files/flmsg/

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FLDigi configuration

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This is what FLDigi looks like when you open it. There are just a few settings that you’ll need to adjust or enable to receive messages.

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Enable RxID. The button turns green when enabled. When RxID is enabled, FLDigi listens for a signal from the transmitting station that indicates which mode is being used & automatically switches you to that mode.

When frequency is centered on 1500 kH, enable Lk button (locks center frequency)

Make sure AFC is disabled (gray). AFC is automatic frequency control which adjusts the frequency to center on incoming signal & often overcorrects. It’s useful on some amateur bands, but not on the ones we’re using.

Make sure center frequency is on 1500 kH (this is the default).

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Next, go to the Configure drop down menu.

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Click on Soundcard, and select Devices

Set Capture to your computer microphone. On a Windows laptop, often that’s something like Microphone Array (Realtek Audio).

Save

Enable PortAudio

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At this point, if your computer microphone is picking up audio, you should see something appearing in the waterfall display here. It probably won’t be quite like this image (which is showing static noise), but there should be some blue lines.

The diamond next to the AFC button is the incoming audio signal level--what your computer is hearing & trying to decode. The diamond is black when there is no signal (<-60.0 dB); green when the signal is good (>-60.0 & <-6.0 dB); yellow when the signal is high (>-6.0 & <-3.0 dB); and red when the signal is too loud or over-driven (>-3.0 dB).

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FLMsg Configuration

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When you open FLMsg it should look something like this: A formatted message template* with a a set of 6 menus at the top: File, Form, Template, Config, AutoSend & Utlities. This is called the Expert User Interface.

*Note: The picture message is an ICS-213 general message, which is a common template used by those of us working in EmComm. But FLMsg has dozens of formatted message templates you can choose from. FYI, FLMsg will open with the last template used.

If instead it looks like this, it is the Simple User Interface (simple refers to the interface, not a slight directed at the user). To enter the Expert User Interface, go to the Tools menu and click Expert Dialog

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To make FLMsg open automatically in the Expert User Interface, go to the Config menu, User Interface

And enable the checkbox next to User Interface = expert.

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Next, click on the Config menu, ARQ Interface (FYI, ARQ stands for automatic repeater request).

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It will open this dialog window. The numeric settings should all be fine as is. Go ahead and enable all of the checkboxes

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That’s it!

  • If you can download and configure the software now, it will give us a head-start on May 17th.
  • If you can’t, don’t worry. We’ll help you when you arrive.
  • We’ll practice receiving messages on the 17th.
  • Make sure you’re signed up to attend HERE.

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  • Saturday, May 17
  • 10:30am  
  • NE Branch, Public Library (6801 35th Ave NE)