for Vision-Impaired Hams
Fldigi is an amateur radio digital modem program with versions for Windows, Mac OS X, and Linux operating systems. This article for vision-impaired hams describes the accessibility of the user interface for Windows and Mac OS X users.
Fldigi for Linux is described in a separate article.
Features of special interest include:
• User-defined keyboard shortcuts
• High visibility font and color options
• Automatic scanning for signals on the waterfall
• Text-to-speech using DigiTalk on Windows XP
• Co-operates with flrig and DXLab Commander.
The fldigi user interface is not accessible for screen readers.
Fldigi is freeware developed by W1HKJ. It includes software modems for the most popular amateur digital modes. The software is available on W1HKJ's Source Forge page. The comprehensive online Users Manual is accessible via a link on W1HKJ's home page.
Fldigi is also pre-installed along with a magnification utility on FldigiVI LiveUSB, which can boot most PCs with a 32-bit or 64-bit CPU.
The main program window is compact (Figure 1), so a large screen and/or magnifier software may be helpful. Images are rendered with high resolution vector graphics. A wide range of high contrast colors is available for text, backgrounds, and indicator lights.
The word-wrap option for received and transmitted text allows you to use large-size fonts without hidden text beyond the margin.
Mac OS X: The main program window size is adjustable, and it does not affect the size of the text and controls. On a 13" screen the minimum window size is 4.1" H x 5.7" W. The maximum size is full screen. Fixed text is 0.08" high, and the frequency digits are 0.13" high. A range of font/style/size options is available for received and transmitted text. The Mac OS X Zoom Magnifier utility works well with fldigi.
Windows OS: The main program window size is adjustable, and it does not affect the size of the text and controls. On a typical 22" screen the minimum window size is 5.4" H x 7.3" W. The maximum size is full screen. Fixed text is 0.08" high, and the frequency digits are 0.15" high, independent of the screen DPI setting. A range of font/style/size options is available for received and transmitted text. Windows Magnifier utility is useful despite some pixelation of small text.
Figure 1. Fldigi main window.
Text to Speech
Fldigi controls and text are not accessible with screen readers, including Mac OS X Voice Over.
With the Windows XP operating system (but not Vista or Windows 7), the DigiTalk program by KH6TY can speak text received by fldigi.
There are three ways to connect fldigi to DigiTalk: (1) manually, using the "Talker" button in fldigi (Configure Menu > "Misc" Tab > "Text i/o" Tab); (2) automatically, by selecting "Auto Connect..." in the same "Text i/o" Tab screen; or (3) manually, using an fldigi macro containing one of the <TALK:x> tags. The DigiTalk program must be running before fldigi can connect to it.
Macros and Keyboard Shortcuts
Fldigi lets you use up to 48 macros, grouped in four rows of twelve control buttons. Each macro in the active row of buttons also has a corresponding function key in the range F1-F12, so the macros also define convenient keyboard shortcuts.
Designating which of the four rows is active requires you to use a mouse. Either click on the row-number indicator at the end of the row, or hover the mouse pointer over the row of buttons and use the mouse scroll-wheel (option in Configure menu > Macros).
You can scan the waterfall automatically by creating a macro consisting of the <SRCHUP> (search up) tag and another macro with the <SRCHDN> tag. For example, pressing the Function key for the <SRCHUP> macro causes fldigi to tune upward in audio frequency to the next signal on the waterfall.
To modify or create a macro, configure fldigi (Configure menu > Macros) to "prompt you to save macro files when closing the program" and "load the last used macro file on startup" [instead of the default file]. Right-clicking on a macro button opens the fldigi Macro Editor window.
Fldigi has a variety of other well documented features. For example: An integrated logging program can be customized for contests as well as routine QSO's. Reed-Solomon identification codes can be sent and interpretted. Fldigi can do automatic callsign lookups and QSL notifications.
Fldigi is a multi-platform (OS X, Linux, Windows) program that vision-impaired hams can use for HF digital mode operation. The high-resolution display works well with magnifier software, but not with screen readers. Large font and high contrast color options are available. User-defined macros can be used as keyboard shortcuts, including automatic scanning for signals on the waterfall. On Windows XP systems, the DigiTalk program adds text-to-speech to fldigi.
Thanks to Skip Teller, KH6TY, for information about DigiTalk.
Peter DeNeef, AE7PD, is an Extra Class amateur radio operator in the U.S. This Web site has no ads or conflicts of interest.
Email: HamRadioAndVision "at" gmail "dot" com.