Welcome to the new FlexRadio Community! Please review the new Community Rules and other important new Community information on the Message Board.
If you are having a problem, please refer to the product documentation or check the Help Center for known solutions.
Need technical support from FlexRadio? It's as simple as Creating a HelpDesk ticket.

Distorted FT8

I have a 6600 with ver 3.2.39 firmware/SmartSDR S/W. Running the latest version of WSJT-X ver 2.4.0 Ever since I got the 6600 I have noticed "Birdies" above and below the main signal. I have been wondering it this was going out over the air. Today a Ham on the north side of town, about 4 miles from me. sent me a picture of my siginal and yup my signal is in fact dirty.
Setting are:
WSJT-X TV level at -6 or lower.
DAX at 55 for about 80 watts out.

The attached picture is what I see. I see that distortion all the way down to around 5 - 10 watts out.

Anyone have any thoughts before I open a ticket?

Steve N4GXX


  • David Decoons, wo2x
    David Decoons, wo2x Member, Super Elmer Moderator

    I cannot open your attachment.

    Make sure the peak level indicator is not going red (above zero). It should be yellow at highest. Set WSJT-X power slider all the way up and set DAX TX to 48. That will set proper output level.

    You may see the "birdies" as you described them on the panadapter during TX but unless you are using full duplex and monitoring your signal on an actual receiver what you see may not be going out.

    As far as your friend, how strong are you to him? If around +25 then you can potentially be overloading his front end and causing him to see stuff that might not be an issue.

    If using a solid state amp you can expect the 3rd order IMD to only be down about 30 to 35dB at best.

    73 Dave wo2x

  • Steve N4GXX
    Steve N4GXX Member ✭✭
    A: He had me on the back side of his 6 Mtr beam at the time. B: He put 20dB of attenuation in line with no change. I see the same thing on my panadapter at the same spacing. I at around the -6dB mark on my input (the yellow bar). I am also seeing trash on a dead carrier into a dummy load.
  • Mike-VA3MW
    Mike-VA3MW Administrator, FlexRadio Employee, Community Manager, Super Elmer, Moderator admin

    Please handle this via a support ticket if you are not doing so already. Thanks

Leave a Comment

Rich Text Editor. To edit a paragraph's style, hit tab to get to the paragraph menu. From there you will be able to pick one style. Nothing defaults to paragraph. An inline formatting menu will show up when you select text. Hit tab to get into that menu. Some elements, such as rich link embeds, images, loading indicators, and error messages may get inserted into the editor. You may navigate to these using the arrow keys inside of the editor and delete them with the delete or backspace key.