Question about WSJT-X "split" setting with Flex 6400

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In the WSJT-X configuration "Radio" tab there is a "Split" option with choices of either "none", "rig" or "fake it."  The latter two choices cause your VFO to transmit on the correct frequency such that the signal is in the center of the rig's passband.  I am imagining that this could be important if you are calling near the top or bottom of the range.  I have not paid attention to this issue yet, but I was wondering if others have used the "rig" or "fake it" settings with a Flex 6400/6600 and if so what are the results?
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Roger J. Buffington

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Posted 3 months ago

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David Decoons wo2x, Elmer

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Split and Fake It are needed on some radios with limited tx bandwidth. As you pointed out it keeps the transmit in the "sweet spot" of the TX bandpass and not near the edges where you could have reduced power due to filter rolloff.

I personally use Fake It and set a tighter TX bandpass.

Just worked KH1/KH7Z on 20 FT8 DXPedition mode from the east coast.

Dave wo2x
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KY6LA - Howard, Elmer

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I use neither -

Flex unlike legacy radios can transmit anywhere in the passband as long as you set your transmit passband wide enough. I have 201 FT8 Countries in less than a year so it must work.

However I usually just pick my own TX frequency and uncheck follow RX as there is little Point joining a pileup on the RX Frequency if trying to work a rare one.

The only time to Check Rig might be when using DXpedition mode
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David Decoons wo2x, Elmer

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And don’t forget DCPedition mode needs 4 kHz Tx bandwidth.

Dave wo2x
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John - AI4FR

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I use fake it on all bands except 60 meters. Watch your TX signal on SSDR and one can easily see the difference, especially as you stated near the band edges. Make sure though that if you use fake it or split that you do not have the SSDR software set to lock the TX frequency. If you do, you'll be causing unintentional QRM, in short, you won't be TXing where you think you are.
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Lucas - W6AER

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John, curious about your comment about 60m since I have also wondered about this. I normally also set "fake it" and works like a charm. How do you go about it on 60? Just leave as none, my guess but likely the expedition mode does not work. Correct?
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John - AI4FR

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Excellent question Lucas and your guess is correct. I manually switch the program from fake it to none while on 60m as the 6700 will not allow any TX outside the specified 60m frequencies/channels. I like to use fake it because I feel it gives a cleaner signal. Watch SSDR while TXing and you'll see the difference especially when you are at the band edges(excluding 60m). When you are near the band edges while in the "none" setting, you can see that part of your signal is being suppressed. Does it really make a difference? I do not know, but the designers say it does so I follow their lead and they have developed these settings for a reason. Using split will also work but it throws more junk up on the screen in SSDR. I use both the wsjt-x and SSDR waterfall to be certain that I am not calling cq on a frequency that is in use, no matter the time slot as I shoot for my daily goal of between 30 and 100 qso's. As for the Dxpedition mode aka fox/hound mode, it is such a mad house right now with its use that I have been avoiding it.
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Roger J. Buffington

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Thanks to all who answered.  I tried running Split/Rig and it works FB.
73 de Roger W6VZV