FT8 and ALC on 6500

  • 1
  • Question
  • Updated 3 weeks ago
  • (Edited)
Hi all
I keep having messages that my signal is bad on FT8.
I am using Windows 10, SmartSDR v2.4.9 and WSJT-x v2.0.0
I am told it is an ALC issue. But I cannot find where to adjust it.
Thanks in advance for your help
Paul F6EXV
Photo of Paul F6EXV

Paul F6EXV

  • 41 Posts
  • 1 Reply Like

Posted 3 weeks ago

  • 1
Photo of Wim


  • 95 Posts
  • 19 Reply Likes
you can lower the audio output on WSJT program itself, look for the sliding bar
on the right to lower the TX power by 2 or 4 dB, you will see your ALC audio level go down on the
flex panel.

You can also click on the DAX icon on  your taskbar and lower the TX Audio level directly

Adjust so that the peak audio level is a bit below the red zone on the Flex audio level indication panel 
Photo of David Ahrendts

David Ahrendts

  • 90 Posts
  • 14 Reply Likes
Agreed. Make sure you're not "pinning" the meter into the red. Back off the WSJT-X v.2.0.0 Pwr bar lower right of the FT8 screen to maybe 80-90% and check the Flex transmit slider meter. Stay in the yellow, not red. Processor off. Should make it crisp and sharp.

AND DON'T FORGET TO UPGRADE TO WSJT-X VERSION 2.0.0 FOR FT8. Previous version is being deprecated and is not compatible with 2.0.0.

David A., KK6DA, Los Angeles
Photo of Larry - W8LLL

Larry - W8LLL

  • 416 Posts
  • 85 Reply Likes
On your level meter you need to stay below 0 DB, as long as the level indicator is yellow and not RED you are putting out a clean signal. The Way I do it is, I leave the Pwr setting on the right side of the main WSJT-X screen up all the way and adjust my audio level in the DAX TX STREAM adjustment in the DAX Control panel, I find once I set this it is good for all bands and power levels and never need to mess with it again but always keep an eye on it to make sure. Power can then be controlled by the SSDR RF Power slider. When others tell you its an ALC issue, they are correct on a  conventional radio where digital audio levels should be set up right before you see any deflection reading on the radios ALC Meter.

Others may do it differently but this works perfect for me.

Photo of Gayle Lawson

Gayle Lawson

  • 50 Posts
  • 19 Reply Likes
Make sure the Processor and DEXP are off.  These functions may cause some distortion.  I also flatten out the TX equalizer.  When you get setup make an FT8 mic profile.
Photo of Paul F6EXV

Paul F6EXV

  • 41 Posts
  • 1 Reply Like
With all this info, I should have a clear signal !
Thanks guys
73 + HNY
Paul F6EXV
Photo of Mark Whatley

Mark Whatley

  • 8 Posts
  • 4 Reply Likes

You should use DIGU also. This turns off all the processing features.