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How do I connect Tokyo HIgh Power HL 1.5KFX to the Flex 6700

Gene - K3GCGene - K3GC Member ✭✭
edited February 2018 in FLEX-6000 Signature Series
Could one of you QRO folk who happen to have a THP HL-1.5KFX provide me with connection details to my new Flex 6700.  With the Yaesu it is simple enough even for me - just plug band cable in and go.  
I have not been able to find any relevant answers for hooking up the Flex 6700.
I would appreciate any help.
Gene K3gc

Completed · Last Updated


  • Ned K1NJNed K1NJ Member ✭✭
    edited February 2017

          You will need a com port, native to the motherboard, on an accessory card, or by using
    a USB to com adapter that has the FTDI drivers.  Then a db9 cable to connect the THP to
    the com port.  You will also need a copy of the latest version of DDUTIL vs. 3. and designate
    a passive listener port to the THP.  You can use the Kenwood protocol for the port.  You may
    have to experiment with this a little bit, but that's what works here.  The THP responds when
    a QSY of the rig sends data to the amp.  Also, keying is done readily through an RCA male
    to RCA male cable from an enabled TX connector on the rig to a keying port on the amp.
    Once you have this set up, you won't even think about it.  It's like having a single-unit high
    power transceiver.  Be very careful driving the amp.  Sometimes the 6000 defaults to full output.
    I usually set drive at 30 to 65 watts for about 350 to 750 watts output on HF.  Read the
    THP manual and become familiar with DDUTIL.  Use great caution at first.  Once you get
    things in order, operation will become quite smooth. It's a good combination, but realize
    that since THP has gone out of business, you must take exceptional care to avoid a
    disaster.  Use a dummy load at low, and then medium output levels to establish settings
    on the rig.  You should not need to use the Flex internal ATU into the amplifier, but the
    solid-state amp will be happiest at low SWR, so use an external ATU after the amp. for
    best results if SWR is a possible issue.  The amp. is an intermittent duty device.  It
    will run CW/SSB at higher levels.  With RTTY, it might be best to keep power output
    at 300 watts or less.  Again, read the THP manual, it's short and to the point.  I
    generally run at 400 to 500 watts output, once in a while I'll go to 800 watts or so.
    I've tested it to 1kw output, but don't operate at that level in the interest of extending
    the life of the amplifier.  I resist that temptation by telling myself that a better antenna
    would be cheaper than a replacement amplifier.
          I hope you have as much success with yours as I have had with mine.

    Ned,  K1NJ
    Oh, one more thing- be really careful.
    This is the way I would be with any amp.,
    not just the THP.

  • Gene - K3GCGene - K3GC Member ✭✭
    edited February 2018
    Thanks Ned,
    One more question.  When you mention db9 cable does that mean serial cable or null modem cable?
    I have noticed the tendency of the 6700 to default to full output.  Is there a fix for that?  Even though the THP is rated for max 100 watts; like you I don't like to run wide open.  I have been running the THP manually with about 40-60 watts from the rig and it is most disconcerting to have it jump up to 100 watts. 
    I have been running the THP for a few years now with my old FT DX5000 so I am quite familiar with it.
    You mention an RCA cable from THP to rig.  I assume (dangerous word) that is along with the DB9 and not instead of - yes?
    Gene K3GC

  • Gene - K3GCGene - K3GC Member ✭✭
    edited February 2018
    One question breeds another.
    I have been studying DDutil and that creates more questions.
    Is the passive listen port a virtual port that is not being used or is it the physical port that i assigned to the amp?
    Under **** radio do I check both Follow SDR and follow Mode? Then I would select type as Kenwood comm 9600 8n1.
    Thanks again,
    Gene K3GC

  • Ned K1NJNed K1NJ Member ✭✭
    edited February 2017

        Yes, the passive listener is the real hardware port you assign to the amp.  It passes band
    data to the amp from the radio via ddutil.  Just check Follow Radio.  I have a null-modem
    adapter in series with a standard cable.  The RCA cable keys the amp.  You need both.
    Also, the "Band Select" switch on the amp. front panel needs to be set to Kenwood.  Make
    sure the amp. follows the radio to the correct band before applying drive.  You may have
    to QSY the radio initially to send data to the amp.
    Ned, K1NJ
  • Gene - K3GCGene - K3GC Member ✭✭
    edited February 2018
    YES!!!!! We have lift off.  Ned, you are my hero
    Gene K3GC
  • WA6FXT MikeWA6FXT Mike Member
    edited June 2017
    Now, the DDUtil is good until you try network remote; then, you'll want to have the Flex6x00 to do the interface.

    This the main reason, I've trying to gently nudge FRS into getting the USB ports on the radio operational for USB I/O devices controllable via the TCP/IP API.


    73's de Mike WA6FXT

    PS: My THP HL1.5KFX manually tuned; but, keyed via the 6700's RCA ports (As is my Pixel Magnetic Loop antenna), at least until the 6700 can control it.
  • Jean DroletJean Drolet Member ✭✭
    edited November 2017
    it is possible to connect the Tokyo Hy-power directau flex6300 ... I would like to use my flex6300 remote

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