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.

Should a 6400M automatically change antennas when changing from say, 20m to 6m?

W2VTV Member ✭✭

Went through the manual online didn't see anything specific to that. I have manually select the antenna each time. TU


  • VE7ATJ_Don
    VE7ATJ_Don Member ✭✭✭

    The Flex will 'remember' what antenna you last used on the band, so if you use ANT2 on 6m and ANT1 on others, then when you flip to 6m (via the band selector) then it will flip over to ANT2.

    The other way to do this would be to set up a profile specifically for 6m and save it. Then, when you want to use 6m, simply select that profile and everything should be set up for you.

    Another way would be to use a 3rd party app like FStack, where you can predetermine all this and have it 'remember' your desired settings.

  • W2VTV
    W2VTV Member ✭✭

    Hi Don, the radio does remember band/antennae changes if I don't power down the radio (fully disconnect it from its 12v supply.) I prefer to shut down the power supply when not in use.

    I'll work on setting up a profile. I'm cautious, as I sometimes make things worse, hi hi.

    Thanks for the input, much appreciated, 73 John W2VTV

  • Mike-VA3MW
    Mike-VA3MW Administrator, FlexRadio Employee, Community Manager, Super Elmer, Moderator admin
    edited August 2022

    You are asking about Persistence.

    Section 18.7 of the SmartSDR user guide in case you want to read up on it.

    Persistence, always enabled on your Signature Series radio, remembers settings from band to band without your direct action so that when you return to a band, your settings are restored. For example, if you are operating on 20m and set the Slice frequency to 14.185, then go to 10m and set the Slice frequency to 28.1 MHz and then go back to 20m, persistence will return your Slice to 14.185 MHz. Resetting the radio to the factory settings (see section 40) will clear the persistence settings. 


  • John KB4DU
    John KB4DU Member ✭✭✭✭

    One caution on the profiles. The auto-save, so any changes made on the fly will be recalled the next time.

  • WX7Y
    WX7Y Member ✭✭✭

    I agree with John, don't trust Profiles, they used to work the way most would think but someone's bright Idea pretty much broke them from being a trusted source to configure your radio and recall your settings.

  • W2VTV
    W2VTV Member ✭✭

    Thanks for the replies. well until I get better versed on setting up a profile, I don't think I'll attempt one.

    As far as persistence goes, it's just not working as described. I'm using just "A" slice, in conjunction with ACLog.

    If I'm 20 and see a spot on 6 and select it, the radio, changes bands, but not antenna.

    This isn't really a big deal, as the 6400 is the primary rig in the shack.

    Again, thanks for the replies, still learning, 73 de John W2VTV

  • Mike-VA3MW
    Mike-VA3MW Administrator, FlexRadio Employee, Community Manager, Super Elmer, Moderator admin
    edited August 2022

    When you change bands, does the TX Profile change. Look for a different name.

    It is possible your profiles are corrupted.

    This may help on Persistance and Profiles

  • VE7ATJ_Don
    VE7ATJ_Don Member ✭✭✭

    So John... I was just testing a theory out and I think I may have seen the same problem.

    If I have two panadapters running -- one on 20m and another on 6m, (picture attached), then it appears I can set the transmitting (red) antenna to either ANT1 or ANT2 without affecting the other. (Note -- I'm running a 6500 with a single SCU, similar to your 6400).

    However, if I change the receiving antenna (blue), then the other panadapter automagically changes to the same antenna (ANT1 or ANT2).

    I suspect this is because there is only a single SCU hence, only one 'receiver' and the working assumption is that both panadapters must be receiving signals from the same antenna port (i.e. a single SCU cannot be receiving signals simultaneously from two different antennae).

    If, however, you are running a single panadapter and simply switching bands between 6m and 20m, say, then persistence/profiles will work as everyone has stated and it will 'remember' that you want to use ANT2 on 6m.

    Maybe that helps???

  • KD0RC
    KD0RC Member, Super Elmer Moderator

    Hi Don, your assumption is correct. All slices on a single SCU radio will always be on the same receive antenna. The slices can be set to different transmit antennas, then when the TX function is selected, the selected antenna will be used for that slice.

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.