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I'm new to Flex. Using either one of these, I guess the slices on my 6400M have to be in the same band. I can't split them up between 2 different bands. True?


  • Ted  VE3TRQ
    Ted VE3TRQ Member ✭✭✭

    As long as your antenna is resonant on the two bands, you can have two panadapters each with a slice on independent bands.

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

    If you have a 6600 or 6700.

    Or you can also have slice A on one band in first panadapter using antenna 1. Then slice B in second panadapter using antenna 2. That is assuming you have two different antennas.

    Dave wo2x

  • KD0RC
    KD0RC Member, Super Elmer Moderator

    Hi John, you can open slices on two separate bands, but as Ted indicated, they will share an antenna. You would normally want each slice in its own panadapter.

    Because there is only one SCU in the 6400, having two bands open means the radio will go into "wide" mode so that both bands can be heard. Wide means that the 3rd order bandpass filters are bypassed. Not a problem for casual operating, but not really workable in a SO2R situation.

    The other thing to consider is that since there is only one SCU, there is only one RF gain setting. So if you are listening on 160 and 6 at the same time (and same antenna), you will likely need to find a compromise setting.

    I often put my 6400 on 10 and 6 simultaneously so that I can watch for band openings. If one or the other is open, I usually close the other panadapter to operate. Since my beam works on 20 - 6, this works well.

    While the 6400 does not have some of the functionality of the 6400 or 6700, it is still a very capable rig.

    Unlike the old days where you could switch frequencies quickly using two VFOs, these radios let you receive on two frequencies simultaneously. Each slice is an independent receiver.

    Enjoy experimenting with the capabilities your new rig!

  • johnn1jm
    johnn1jm Member ✭✭
    edited August 2021
    Okay I see. When I am in multiplex mode with a PC or Mac, the same thing- I'm in wide mode bypassing the filters if on 2 different bands.
  • KD0RC
    KD0RC Member, Super Elmer Moderator


    It sounds like you are getting a good handle on your new radio. Another feature that you will want to look at is Full Duplex (FDX). Ken, NM9P has some excellent videos on YouTube showing you how to adjust your transmit audio using FDX. When I first got my 6400, I saw that it would do full duplex, but dismissed it as a Satellite operations only kind of thing. I was completely wrong - it turns out that it is a really powerful tool to be able to check out your own signal quality.

  • johnn1jm
    johnn1jm Member ✭✭
    Thanks, Len. Much of my dilemma was that I was not seeing 2 panadapters. Now that I figured out how to do that, I'm happy :) . I'll try full duplex.
  • John KB4DU
    John KB4DU Member ✭✭✭✭

    If you don’t mind using a tuner, the antenna doesn’t need to be resonant. I use an 80/40 fan dipole on all bands above 80 with an automatic external tuner. It is a little cumbersome to tune on each band change, but for working one band with one slice and watching/monitoring another with a second slice, it’s ok.