My Linux Digital Setup

K7JLJ.com
01.06.19

What do these things have in common?  They frustrate the heck out of me when trying to get them all to play nice together!

This is the second time that I have setup digital on Linux in the past two years and while I somehow I got them all to work nicely together again, I spent hours fiddling on it the second time, so I'm writing it down for next time. :)

This "guide" assumes that you are already running a Ten-Tec Eagle (TT-599) on Linux Mint 19 (any Ubuntu based distro should work also) and have a SignaLink USB and all hardware is connected properly.

Resources:

LINUX MINT 19 SETUP

Make sure you are part of the "dialup" group.
This gives permissive rights to use the USB ports or "TTY" ports.

In the terminal type the following command:
sudo usermod -a -G dialout <username>

Find which USB ports your SignaLink and Radio (TT-599) are on.
lusb_output

  1. Plug in just the SignaLink and run lsusb to get the location.
    Bus 001 Dev 011..... Audio CODEC.

  2. Plug the TT599 in and run lsusb again to find it's location.
    Bus 001 Dev 015... Primax Electronics.

Adjust your computer volume in/out on the SignaLink to 100%.

  1. Click the speaker button in the lower right corner of your screen, then the Sound Settings link.
    vol_1

  2. While your SignaLink USB is connected you will see it listed as something like the "Audio CODEC" and in the same port you found it on using lsusb above.
    vol_4

  3. Adjust the Analog input & output to 100%

FLDIGI SETUP

FLDIGI<em>Audio</em>Source

The best way I found to use the Ten-Tec Eagle with FLDigi is by controlling through the default FLRig server.

The HamLib and CAT file you can find on the internet is not reliable and does not allow rig control when using WSJTX to work FT8, JT-65, etc. that using the FLDigi server does.

Notice that the image above shows the port to the radio as /dev/ttyACMO which does not look like the lsusb result you got earlier. Each program seems to ID the device a little differently.

If in doubt, use that modal screen with the radio USB cord unplugged and then plugged in again to see what pops up in the choices.

Once you initialize this setting, you should see everything talking and controlling!

Refine your input level for best contrasting waterfall.
Go to 14080 and setup FLDigi for RTTY-45, then track a few signals by clicking on a the channels in the left viewer.

You want semi-strong signals and the goal is to adjust the contrast to a point that gets the best translations. Obviously the band conditions and traffic has to be good to do this.

Watching the waterfall, adjust your sound RX knob on the SignaLink, preamp on the TT-599, RF gain on the TT599 until as much yellow "splatter" is removed to get good translation. Contrast is what we want, but the weaker the signals the less we will have. It's mostly experimentation and knowing your band condition limitations.

Should look something like this...
Adjusted_Levels

Notice the display settings on FLDigi make a difference on the waterfall also. Default -20 to 20db is shown, with the SQL level adjusted over the noise floor. Play around with the SQL level to match the S:N level being received.

Adjust the radio TX to be just under the level of ALC.
With your TX and RX pointing at the 1200 position and the DLY all the way CCW, adjust the digital output gain on the radio so that it's just under ALC activation levels.

Getting to the Digital Gain Mode
Normally the MIC gain is on and seen in the lower left corner when using the radio in SSB.

If you tap the MIC button, you will see a number between 0-100 (gain % level) flash next to word "MIC" on the screen. This is your MIC gain for using SSB and is adjusted with the MULTI knob.

In FLDigi, go to an empty channel and use the RTTY mode to test your output level. With your radio power turned down to 1W try tuning the radio through the button in FLDigi.

To adjust the DIGITAL gain, long press the MIC button until the MIC label disappears. You are now in DIGITAL gain mode.

Short press the MIC button again and get ready to adjust the % gain level until the ALC just stops activating.

Hit the CQ button on FLDigi and watch ALC light and adjust the MULTI knob until it just stops lighting up.

For me this was between 10-12%.

CONCLUSION

It's not so bad if you know what to look for. :)

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