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Heil Sound microphones and Flex, are there compatibility issues?

I was about to purchase a PR781 to plug into my 6400 until I saw that the compatibility list on the Heil web site did not include Flex. Several 3-Pin XLR mics are listed (PR10, PR20/UT, PR28, PR30, PR40, PR77D, The Fin) as compatible, but not the Heil PR781 which is reportedly designed for amateur radio use. The cable I had intended to use is Tisino XLR to 3.5mm with a separate PTT foot switch. Should I avoid the PR781? Is another Heil mic highly recommended? Thanks!

Best Answer

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

    All Heil mic’s can work work FlexRadio if you have the correct cable.

    Many use the PR781. I’m sure others will comment.



  • Lou KI5FTY
    Lou KI5FTY Member ✭✭

    I have the PR781G and love it. Works great.

  • Mike Steventon
    Mike Steventon Member ✭✭✭

    I have the PR-40 and love it. Works great! W2IHY eq and comp, then balanced input to the Flex.


    Mike G4GWH

  • Trucker
    Trucker Member ✭✭✭

    Flex Radio sells Heil microphone adapter cables that work with the 781.



  • mark1161
    mark1161 Member ✭✭

    Good Evening All,

    I have a FLEX 6400M and am using a Heil PR10 with a generic XLR to 3.5mm Amazon cable. I am seeing no output on the panadapter. I am keying the rig with PTT but no output. Can I assume the cable is incompatible with the radio?

    Any assistance would be appreciated.




  • WX7Y
    WX7Y Member ✭✭✭

    Sounds like indeed the cable you are using is not wired correctly for the 6400.

    Thinking back the 6400 1/8" MIC jack at least on early 6400 Radios is slightly different then the 6600 which is a Pseudo Balanced MIC interface.

    I would try tying the MIC - connection to the Shield / Ground and the MIC+ to the tip, Make sure your MIC selection is set for MIC.

    If this doesn't work you may have to connect it to the accessory Jack or Line Jack.

  • Neil D Friedman N3DF
    Neil D Friedman N3DF Member ✭✭✭✭

    The user manual does not indicate any difference between the 6400M and the 6600M in the 3.5 mm mic connector (the 6600M has an additional 6.3 mm balanced audio input).

  • Neil D Friedman N3DF
    Neil D Friedman N3DF Member ✭✭✭✭

    The user manual states mic + to the tip, mic - to the ring and ground or shield to the sleeve.

  • WX7Y
    WX7Y Member ✭✭✭
    edited March 2023

    YES Neil, I know they are wired the Same on the 3.5mm Jack and the 6400 doesn't have the 6.3mm, I was just suggesting this to Mark for the CABLE he had nothing More nothing Less, sometimes the Chinese get there wires crossed.

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