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How do I Use a USB Cable BDC to control a EA4TX Interlock Box

Steven Lott Smith
Steven Lott Smith Member ✭✭

Wish to use Two FlexRadio 6600's

But only One Transmit signal at any given moment

Equipment on hand 2 FlexRadio 6600's

One EA4TX Interlock Box

One USB Cable with FiDI Chip

Any specific hookup and setup tips, please



Best Answers

  • KD0RC
    KD0RC Member, Super Elmer Moderator
    Answer ✓

    Hi Steve, I don't think that it uses a BCD cable. From the EA4TX web site:

  • KD0RC
    KD0RC Member, Super Elmer Moderator
    Answer ✓

    Glad to help!


  • Len,

    Dude thanks for the very fast reply

    And that is good news you gave me




  • Len can you advise further on setting to get the EA4TX Interlock Box working

    apparently I need to change some settings of the radio

    I tried a few but no joy, yet

    Bother rigs the Accessory Jack is wired to respective db9 connector of the EA4TX Interlock box

    But do I set the Flex radios to PTT Inhibit or something else or a combination of settings

    I am attempting to set up for Multi Single

    I have the EA4TX Box set I believe but lost of the Radio Settings...

    Radio Setup TX Inerlocks - TX Req active High or Low ????

    Transmit Band settings ACC TX Checked yes or No or is it the ACC TX Req to be checked ?

    Thanks in advance

    Steve KG5VK

  • KD0RC
    KD0RC Member, Super Elmer Moderator

    Hi Steve, I'm not sure what the EA4TX box is expecting in terms of Flex settings. Is there anything in the documentation?

    One way to approach the problem is to connect both rigs to dummy loads with the RF Power turned down. Now try all of the conditions that you are trying to protect against to see how the EA4TX unit controls (locks out) the Flex rigs.

    If you can only get one rig to transmit at a time, you will have your answer. If there are conditions that allow both rigs to transmit simultaneously, then you need to study those conditions and/or try different combinations of the Transmit Band Settings to see the effect.

  • Len,

    Thanks That is what I am attempting

    just have not found the right combination, yet

    The EA4TX is looking for signal called INHIBIT, which will be used by the Interlock to perform blocking

    So I guess I will look for that in the SDR Manual to give me a better clue

    I am just sure someone has used this Box with a FlexRadio and knows the "secret" combination

    Once I find the Secret combination I will share it



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