TM-D710GA Fan modification for APRS

Discussion in 'General Technical Questions and Answers' started by K7CJ, Nov 28, 2016.

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  1. K7CJ

    K7CJ Ham Member QRZ Page

    Hi all, I just recently purchased the Kenwood TM-D710GA from HRO over their holiday sale. I wanted to get one to play around with APRS, etc. For now, I just want a fixed station setup on the air. I finally got it working as per our local 'regional' settings, etc. APRS seems to be working fine.

    The only catch was that my new D710GA fan was on *all* the time -- and it wasn't very quiet. It was quite loud in fact. Prior to the new radio, the room has always been fairly quiet -- despite all of my other gear, computers, TV, etc.

    I happened upon an old article of a ham (I think from Poland?) who had modified his D710 with a replacement fan. The fan he suggested was available but a little expensive. Amazon recommended another fan which was helpful since I use the same brand for my CPU fan inside my custom PC. I didn't realize they made small, project fans though.

    I don't have any before/after audio of the fan but I can certainly supply pictures and/or a youtube videe of my modification if there's interest in seeing how I did mine. It's *very* easy -- probably the easiest modification I've ever performed. (Very little soldering required. Actually you can get by without soldering but I would recommend soldering the wire connections.)

    So here's the fan I used which fits perfectly:


    The fan comes in a kit form and has some extra cables. I attached the main fan lead (3-pin) to the LNA cable, which drops the speed slightly, to help reduce fan noise. With this cable, the fan is rated at 11dba. (The stock fan is 22dba but it sure sounded louder than that since it was always on.)

    1. Remove the (8) screws from your D710 main unit (with speaker grill)
    2. Remove the (4) long, fan screws from the fan housing. Set aside the wire protector.
    3. Unplug the fan from the main circuit board
    4. Remove the stock fan
    5. Carefully pry the red/black wires from the stock fan housing and free them from the routing spaces.
    6. Desolder the red/black wires from the stock fan (there will likely be solder on the ends. This is good.)
    7. Take the 3-pin to 2-pin converter cable from the Noctua kit and cut off (about 2cm from the connector) the 2-pin connector. Remove the black flex shell from the converter cable. These can be tossed.
    8. Cut a small piece (1") of heat-shrink tubing sized for the two wires and slide it over the end of the converter cable -- toward the end of the 3-pin connector.
    9. Use wire strippers to expose no more than 5mm of clean wire from the converter cable red/black wires.
    10. Solder the red/black wires from the Kenwood connector to their respective counterparts (red-red, black-black) of the converter cable.
    11. Take a small piece of electrical tape and cut in (4) equal pieces. Use (1) piece to cover each newly soldered joint.
    12. Slide the heat-shrink tubing over the (2) pieces of tape and use heat-gun to shrink the tubing.
    13. Mount the new fan and feed the wires thru the chassis.
    14. Screw the (4) long, fan screws into the wire grill and into the fan. Be careful not to over-tighten. Watch for the thin, rubber "anti-vibration" gaskets on the new fan. You may need to hold these down with a finger while tightening the screw.
    15. Route the (rather) longish cable inside the radio. It's sealed fairly well so there's no likely issue of anything shorting.
    16. Plug Kenwood fan connector back into circuit board.
    17. Reinstall the (8) case screws.


    1. If the extra-long cable bothers you then I'm sure it can be modified as the yellow lead from the new fan isn't used. In theory you could easily snip it at the end of the first connector and go from there; however, then you may not be able to use the LNA cable. I don't believe there's any reason to modify its length.
    2. The fan mfg label should be seen from the back of the main case. (This means the airflow will flow out.)

    Enjoy the new fan! I'd guess it's about 75% quieter than before!

    PS. From memory, I believe this is the stock fan:

    Please let me know if you guys want to see pictures and/or a video of the modification.

    -Nick, k7cj
    K6CLS and K5URU like this.
  2. OH6KNW

    OH6KNW Ham Member QRZ Page

    Thank's Nick, just got my TM-D710 modified based to your recommendations... Now we have peace in house... Big difference, fan can be barely heard... :)
    K7CJ likes this.
  3. K6CLS

    K6CLS Ham Member QRZ Page

    Great! Thanks for doing the legwork on this. My (mobile) D710 is driving me nuts.
    K7CJ likes this.
  4. K7CJ

    K7CJ Ham Member QRZ Page

    Thanks guys. The new fan worked well for me for well over a year with zero issues. Alas, I had to sell my D710GA recently but always looking forward to a new radio. ;o)
  5. K5AHH

    K5AHH Ham Member QRZ Page

    Good job. I decided to check out the CFM of the new fan to see if you had overlooked it having potentially LESS airflow. I was happy to see it has more! The old, stock fan is 5.3 CFM, but the new fan is 6.6 CFM the way you have it set up. It has the capability of 8.2 CFM of airflow, but it would be a bit louder. Still, you wanted a quieter fan and also got the bonus of a slightly cooler heatsink. I'll bookmark this fan for sure.
  6. OH6KNW

    OH6KNW Ham Member QRZ Page

    Thank you for these instructions, just got my 2/5 Kenwood updated with new silence fan :)

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