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How do I get FT8 to work on a UK FLEX 6400?

stevew_m0rfc
stevew_m0rfc Member ✭✭
edited September 2025 in Third-Party Software
Hi all,

Just got back into Flexing with a new 6400, but with JTDX, I cannot for the life of me get 5357 to accept that as a frequency for DIG to transmit on.

Have TX filter set to 0-3000 and JTDX to "none".

Everything looks like all the other posts I have searched for, but nothing seems to do - can someone screenshot or send me a guide with it working?

I have the correct UK turf.

73 Steve
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Answers

  • stevew_m0rfc
    stevew_m0rfc Member ✭✭
    edited September 2025
    After more searching, I found Dave Spencer's answer, "Are you in the UK? If so, you must transmit below 1000hz, including the width of your transmission" sorted it!
  • Mike-VA3MW
    Mike-VA3MW Administrator, FlexRadio Employee, Community Manager, Super Elmer, Moderator admin

    This seems strange. The radio does not know what transmit frequency you are actually transmitting on. This sounds like a restriction of sort in JTDX.

    Is there a law in the UK that requires this restriction?

    A few screen shots of JTDX would help understand the root cause.

  • Erik Carling EI4KF
    Erik Carling EI4KF Member ✭✭✭✭

    Is it not written into the relevant TURF file for UK radios?

    In the UK, amateur radio operation on the 60-meter band is restricted to specific frequencies, primarily 5354 to 5358 kHz, with a maximum bandwidth of 2800 Hz, and includes digital FT8 operation up to 5357.950 kHz

    With FT8 starting at 5357, Steve is clearly correct in asserting his limitation to TXing below an audio frequency of 1000Hz. The radio, with the TURF for UK, will prevent out of band use. When I bought my 6400M it came with this restriction and Flex provided me with the EU TURF which opened up the whole band as we have it in EI and EU generally.

    Erik EI4KF

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

    ah, 60M band… I missed that. Yes, you need to keep the TX bandwidth on the radio to whatever the UK law is.

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