Rig Monitoring with Flrig for Linux


  Flrig is an amateur radio transceiver-control program that runs on Mac OS X, Linux, and Windows systems. This article is for vision-impaired hams who want to use the Linux version of flrig for local rig monitoring. The Windows and Mac OS X versions are described in a separate article.

   Free Linux and flrig software combined with modest computer requirements make this a low-cost option for a rig monitor.


Flrig is freeware developed and distributed by W1HKJ. The current version of flrig for Linux is available from W1HKJ as source code and an application for Puppy Linux. Links to packages for the major Linux distributions are at the bottom of W1HKJ's Download page. These links include flrig PPAs for Ubuntu in Kamal Mostafa's archive. Flrig is also in the Ubuntu Software Center. (Compare the version number with the current version on W1HKJ's site.)

   Flrig is also pre-installed on the fldigiVI LiveUSB.

   A list of supported radios is on the flrig Web site. Flrig has a control panel for each model.

Installing and Configuring Flrig

  A separate page gives examples of how to install and configure flrig.

Connecting the Radio to a Computer

   Push-to-talk is via CAT control (if your radio supports it) or hardware PTT. The Setup section of the flrig Help page explains how to configure the program to use a CAT serial port.

   The basics of CAT interfaces are described in the article on rig monitoring. For this review a MicroHam USB Interface III was used for the serial data connection. (Details are on a separate page.) Like many other commercial USB interfaces, it works with multiple operating systems, including Linux. No custom device drivers are required. Flrig does not use the sound card.


   The flrig control panels are compact, so a large screen and magnifier software may be helpful. Flrig renders images with high resolution using vector graphics. Flrig controls are not accessible with keyboard shortcuts or screen readers.

   There are two options for displaying the Main Dialog Window. The default is the Wide User Interface (Figure 1) with a larger frequency readout and a wider, adjustable-width window. The other interface (Figure 2) is taller, and the size is not adjustable.

Figure 1. Flrig Wide User Inteface.



Figure 2. Flrig Narrow User Interface.



   On a 15" screen the wide interface is 1.8" high with a width of 7.5 inches or larger. The VFO-A (left) frequency readout is 0.35" high. The narrower interface is 3.4" H x 4.4" W. The VFO readout text is 0.2" high.

   Except for the frequency readout, the text size in both windows is 0.1" high.

   High contrast colors are customizable using a wide range of individual options for text, backgrounds, meters, readouts, indicator lights, and sliders. These and other configuration options are described indetail on the online Help menu.

Rig Monitoring

   Flrig updates the meters and rig settings in the display by polling the radio. The Polling Dialog Box (Config menu > Xcvr select > Polling tab) configures how flrig follows each control on the radio.

   For example, when the polling cycle number for Volume is set to zero, flrig controls the radio volume, but it does not poll the radio, so changes made with the real radio control volume control are not displayed on the screen. For a Volume polling cycle number of one or higher, Flrig both controls the radio audio level and updates the position of the Volume slider and the digital Volume readout. Higher polling cycle settings increase the time between updates. This is a useful option because the latency between the radio and flrig depends on the number of controls that are polled each cycle.

   During transmissions the high resolution S-meter is replaced by an SWR meter. Clicking on it switches the display to an ALC meter.


   The flrig Memory menu makes it possible to save and select frequency/bandwidth/mode settings in a database stored in computer memory.

Using Flrig with Fldigi

   Flrig can cooperate with the fldigi digital modem program for Linux (Figure 3).  Fldigi accessibility is described in a separate article.

Figure 3. Fldigi with Flrig on Linux.




   Flrig for Linux can serve as a local rig monitor for vision-impaired hams. The high resolution display works well with magnifier software, but not with screen readers. Flrig can cooperate with the digital modem program fldigi for Linux.

For More Information

Flrig Help page

Installing and configuring flrig for Ubuntu

Author Information

   Peter DeNeef is an Extra Class amateur radio operator in the USA. This website has no ads or conflicts of interest.
Email: HamRadioAndVision "at" gmail "dot" com.

rev. 2/15/2015

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