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Microphone Cable RF problems and Cable needed for Heil PR 781 connections

GDECASTRO
GDECASTRO Member ✭
edited November 2025 in Peripherals & Station Integration
Hello, 1. I do have a request for hams that had experience Radio frequency on the transmission with the microphone FMH3 on a 6400M or should I limit the question to the cable of the mentioned microphone.
2. what is the best cable to connect to a 6600 M a Heil PR781 ?
Thanks
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Comments

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

    Which mic input do you intend to use? Balanced or pseudo-balanced?

  • Neil D Friedman N3DF
    Neil D Friedman N3DF Member ✭✭✭✭
  • GDECASTRO
    GDECASTRO Member ✭
    I do not the answer to your question
  • GDECASTRO
    GDECASTRO Member ✭
    I do not know the answer to the question
  • Neil D Friedman N3DF
    Neil D Friedman N3DF Member ✭✭✭✭

    critical for selection of proper cable.

  • WX7Y
    WX7Y Member ✭✭✭✭
    edited November 2025

    On the Heil PR741 which is a Balanced MIC if your troubled with RFI getting into your MIC Audio I would keep it all Balanced on the radio. I would buy a XLR to fit the PR741 MIC to a 1/4" Phone plug for the FLEX6600/ 8600 like is used in the Music industry like this one on AMAZON

    https://www.amazon.com/Tisino-Female-Balanced-Interconnect-Quarter/dp/B07JVBS78Z/ref=sr_1_5?crid=2O0Z3XEI146W3&dib=eyJ2IjoiMSJ9.Z6Oa2CwhHcYm_VI49Mc31sdUfUwXo_iRMuA3P_Mf4nnXzdjc1LofO287f3lFzKDPFn2_v-tqx5MsPzwNYAqNubNbReRYc-okKqOzKUkMnDZ0aYw3I4czHF4MyPtPkZGTqRFfUkv5QhoF0GN9VYKxKfNFGbQj6ZfkyIg7c5eLjunVLkKnZfjNhDeDcPsuEVRThLrxzd0rfJ1GbLHIspadaaXzR9O9cBM0fPVGi_mveIA.5MitvwIQQkA8OM5iL0iKIFKrvu7D4OQCknUAAUMpGVQ&dib_tag=se&keywords=XLR%2BMIC%2Bto%2B1%2F4%22%2BPhone%2Bplug%2Bcable&qid=1763926476&sprefix=xlr%2Bmic%2Bto%2B1%2F4%2Bphone%2Bplug%2Bcable%2Caps%2C159&sr=8-5&th=1

    On the 6400 it does NOT have the Balanced input but just the 1/8" pseudo-balanced which MAY NOT help with your RFI because it ties the MIC-- and signal to Ground together.

    Hope this helps and 73

    Bret WX7Y

  • GDECASTRO
    GDECASTRO Member ✭
    Thanks a lot

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