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.

ATU and antenna matching

PFSOD Member
I have a 6400 w/ATU. Should I be able to successfully tune to a G5RV Jr which has a 300 Ohm lead? I have that lead running to the 6400 with 75' of 50 ohm coax. I'm just not sure it's working. Also, I lost my audio again.


  • John KB4DU
    John KB4DU Member ✭✭✭✭

    Out of curiosity, I suggest an SWR meter. The internal tuner will transform a 3:1 to a more useable value.

  • Ha Gei
    Ha Gei Member ✭✭✭

    If the tuner stops with sucess , and you get good reports.. all is well..

    If the tuner cannot tune sucessfully or you get bad reports.. something is wrong and needs investigation.

  • Mike-VA3MW
    Mike-VA3MW Administrator, FlexRadio Employee, Community Manager, Super Elmer, Moderator admin

    The ATU on a 5400 will tune an SWR of about 3:1 or less.

    Since G5RV's are originally designed for 20M try that band first. It might tune as its impedance should be around the right amount.

    However, it is likely you'll need a broader range Antenna Tuner such as an LDG to tune that antenna.

    If you have any readings from an antenna analyzer, that would be helpful.


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.