Kenwood Tkm-707 Mods __exclusive__ – Trusted

Kenwood TKM-707 is a vintage marine HF/SSB transceiver known for its rugged 150-watt output and general coverage receiver (500 kHz to 30 MHz). While highly capable in its original marine role, it is frequently modified by enthusiasts to expand its frequency range or adapt it for amateur radio (HAM) or CB use. Common Modifications

  • User controls / ergonomics

    Part 1: Why Mod the TKM-707?

    1. Firmware Update: Check for firmware updates on the Kenwood website and install the latest version to ensure you have the latest features and bug fixes.
    2. Adjust the TX Power: Optimize your transmission power for better efficiency and reduced interference.
    3. Disable Unwanted Features: Disable features like the beep tone or confirmation tone to minimize distractions.
    4. Optimize the Squelch: Adjust the squelch settings for improved noise reduction and reception.
    1. Disconnect power – Internal capacitors hold a charge, but step one is safety.
    2. Remove the top and bottom covers to access the main PCB.
    3. Locate the Diode Matrix (D508–D515): On the TKM-707, look for the Control Unit (X57-3310-XX). You will see a row of surface-mount diodes near the main CPU. They are labelled with "D" numbers.
    4. Identify the jumpers: You are looking for diodes or zero-ohm resistors in positions typically labeled for "Country Code."
    5. The standard mod:

      Last updated: 2025 (based on reverse engineering by VK3HZ, N6WS, and JA1HBS). Kenwood Tkm-707 Mods

      Why you need it:

      This turns the clarifier from a "fine tune" into a proper "voice finder." No more asking the other station to re-tune their Drake. Kenwood TKM-707 is a vintage marine HF/SSB transceiver

      Goal:

      Improve frequency stability.

      • Apply only one mod at a time (or predefine combinations), documenting exact component values and placement with photos.
      • Re-run the full measurement battery after each mod.