FT 991 and MD100

Discussion in 'VHF/UHF - 50Mhz and Beyond' started by K3XI, Sep 3, 2016.

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  1. K3XI

    K3XI Ham Member QRZ Page

    Just ordered a FT-991 I want to order the MD100 Mic and wonder if this mic works well on FM
  2. KD8DEY

    KD8DEY Ham Member QRZ Page

    general consensus by other MD100 owners as used on other Yaesu radios..
    Yes, compared to the standard stock hand microphone.
  3. K3XI

    K3XI Ham Member QRZ Page

    Thanks for the reply, I use them on my other yaesu gear and they work very well. Just wondering if
    also works well on the FT991 I have seen some mixed feelings on this rig
  4. KW4EK

    KW4EK Premium Subscriber QRZ Page

    Keep in mind that the FT-991 includes a parametric equalizer so that you may also customize your mic's sound based upon your chosen mic and voice characteristics. So you are not simply stuck with the stock sound of any mic you may choose.

    I do not have an FT-991, though I am considering getting one for field use and as backup radio, but I do have an FT-950 and the MD-100 desk mic and found it to sound very nice. I also built an interface so that I can use a gaming headset (Turtle Beach XOSeven) and boom mic (condenser type mic) for hands-free use along with a foot pedal PTT switch, which works great for special events or contesting scenarios, or just plain sitting back and relaxing in a ragchew. Both have received compliments on their sound on the HF bands, but I have yet to try either on FM as I have not yet built an adapter cable to interface the mics to my FT-8900 quad-band radio (eventually I will get around to such to facilitate net control duties).

    If I recall correctly the FT-991 uses an RJ-45 mic jack rather than the typical 8-pin DIN connector Yaesu typically used on their "base station" HF radios. I do not recall off hand whether the MD-100 microphone includes an RJ-45 to RJ-45 cable as I recall mine coming with an RJ-45 to 8-pin DIN (round) connector, so you may need to purchase an RJ-45 to RJ-45 cable to connect the mic to the FT-991. Although, as I think about it I think it is possible to reverse the cable to possibly get an RJ-45 radio connector as there is also an 8-pin DIN connector on the microphone base, so there may not be an issue there.

    If you would, after you have spent some time using your radio and getting familiar with it, I would really appreciate any comments on your experiences with it (private comments are fine if you prefer) and what you like and dislike in the radio since I am considering purchasing one. Thanks in advance.
  5. K3XI

    K3XI Ham Member QRZ Page

    Hi Ethan and thank for the reply, from what I am reading some has had trouble with the audio. But it just
    may be the way it is set up with the eq. Years ago we did not have to do all the tricks to have things sounding good. But today with most rigs it seems it is just to get you on the air and then set your audio how you want. I have the FT5000 and FT1200 which I use the MD100 and most people don't believe it is the MD100.

    It really sounds good on both rigs if the eq is set right. The MD100 has a rather flat response with the new rigs, but it can be set as you know for a lot of different voice types. I was just wondering if anyone has used it on FM and if corrections need to be made. I can always test myself. I mostly operate cw but I do like to get one phone once in a while and the reason I bought the 991 is for 2 simplex.

    I like the bigger rigs. Oh by the way, I never use processing. I find no need for it. Guess it depends what you like. Yes the MD100 can be changed to the RJ45 just reverse the cord and the RJ45 goes to the rig and the other end to the eight pin on the back of the mic. I have a friend that lives just a 1000 feet from me and he love his FT991, and I might add it is very critical. So thought I would give it a try...... I will write you call down and get back to you once I give it a once over. Thanks again for the info...73
  6. IU0DMP

    IU0DMP Ham Member QRZ Page


    Attached Files:

  7. K8JD

    K8JD Ham Member QRZ Page

    I got a FT990 with no Mic and had to wire up a junk base radio mic from Standard commercial radio, a MP501 that had a failed element, . I found a good magnetic element from an older Motorola hand mic and wired up the cable with an 8 pin plug to match the Yaesu socket. It worked.
    A bit of work to see if the newly acquired rig actually worked on SSB and FM. It does. :rolleyes:
    I am a CW ham :D
    ILUCKY likes this.
  8. KJ7AOL

    KJ7AOL Ham Member QRZ Page

    Thought I would jump in to comment on this.

    I have a Yaesu FT-991 (not 991A) and purchased an MD-100 as a desk microphone based on info saying it was compatible. However, when I tried to use the microphone, I received multiple reports of a very loud hum in the background that was overriding my voice. I contacted Yaesu and learned that the original FT-991 was not completely compatible with the Yaesu MD-100A8X. Apparently, there is a grounding problem with the TFT screen. They sent me a short grounding wire for free that I could solder into a point on the front board, and fasten onto a screw on the radio. After some problems due to my originally sloppy soldering, I was able to complete the fix and the mic now works pretty well. There is still a 60 hz hum in the background, but it is low and does not interfere at all with use of the mic.

    Beware: pay close attention to the photo Yaesu sends you to make certain you have the correct connection points. Also, do not allow solder to bleed over from the grounding point to an adjoining solder point. If solder bleed-over shorts to that point, you will lose functionality of the buttons on the front face of the radio. If that happens, carefully remove the excess solder and make certain there is no connection between the ground and the solder point to the right. After doing that, everything worked normally aga
  9. N2DZ

    N2DZ XML Subscriber QRZ Page

    Is this still a thing with the 991 and md 100a8x? I was thinking of picking one up for my non-A 991 but I am not technically inclined for soldering nor do I have the equipment for it. Tried calling Yaesu but no response.
  10. KU4GW

    KU4GW Ham Member QRZ Page

    Tim, I've been using a MD-100A8X mic with my FT-991A since July 22, 2020 and get unsolicted good audio reports on how it sounds. I don't even use the built-in parametric equalizer in my FT-991A because all my friends on 75 meters say I sound better without it on. I do have the switches on the bottom of the MD-100 set as follows: Main in Filt position, High Emphasis set to On, and Low Cut set on position 1. Enjoy your new rig! I love mine and use it on phone, CW, FT8, and Feld Hell/Hellschreiber. 73!


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