Welcome to the FlexRadio Community! Please review the new Community Rules and other important new Community information on the Message Board.
The latest SmartSDR Software:
SmartSDR v4.2.18 | SmartSDR v4.2.18 Release Notes
SmartSDR v3.10.15 | SmartSDR v3.10.15 Release Notes

The latest 4O3A Genius Product Software:
The latest 4O3A Genius Product Software and Firmware
How to Receive Technical Support::
If you are needing assistance with FlexRadio products, 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.

Is there a way to read the L and C values of the ATU and/or to manually set them?

rssutton9
rssutton9 Member ✭✭
in SmartSDR for Windows

I have a 6400 feeding a 132 ft. end-fed antenna. Using the ATU it takes several attempts on 75 meters to get a good match. I'd like to lift the hood and see what the atu is doing.

Best Answers

  • Mike-VA3MW
    Mike-VA3MW Administrator, FlexRadio Employee, Community Manager, Super Elmer, Moderator admin
    edited April 2021 Answer ✓

    @rssutton9 What version of SmartSDR are you using?

    Also, don't for the internal tuner is only designed to do an 3:1 SWR or less reliably. Don't confuse the ATU in the 6400 with a proper antenna tuner that can far exceed that operational range.

    73

  • John KB4DU
    John KB4DU Member ✭✭✭✭
    Answer ✓

    This is a common limitation of internal tuners. They are intended to support operations with an antenna that is resonant in the band but is being used at a frequency slightly off the resonant point. An end fed antenna could have a feedpoint impedance of 3000 ohms or more (60:1). Its going to need an impedance matching transformer.

  • Mike Steventon
    Mike Steventon Member ✭✭✭
    Answer ✓

    On page 13 of the 6400 and 6600 user manual it quotes:

    8.3 - 300 Ohms (80m – 10m) 6.7 - 150 Ohms (160m and 6m)

    -for the atu range.

    I find it quite good on my long wire, but you cannot beat a decent manually operated Palstar AT2K to have control over the rubbish I **** in my back garden!

Answers

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.

Comment As ...

Categories