D-104 loading...

Discussion in 'Amplitude Modulation' started by W1BR, Jan 27, 2021.

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  1. W1BR

    W1BR Ham Member QRZ Page

    My voice has a lot of lows, and I am getting reports of good audio, but a few guys on 160 have suggested if I
    could cut the "mud" a bit I'd sound better. Mike is a D-104 with a Koby cartridge and the K7DYY processor

    The simplest solution would appear to be as easy as adding some load resistor to element below the
    several megs that the board provides. I am not sure that is the best approach even though it seems
    the easiest.
  2. K1LKP

    K1LKP Platinum Subscriber Platinum Subscriber QRZ Page



  3. W1BR

    W1BR Ham Member QRZ Page

    160 meter AM, on the Grayhair net... LOL. I am bald. Maybe that is the problem with the excess lows.

    BTW, what is this SSB stuff?
    Last edited: Jan 27, 2021
  4. KA0HCP

    KA0HCP XML Subscriber QRZ Page


    Wireless Girl comments on the same problematic bassy response with these components, with no 'fix'. She says heavy equalization would be required to adjust the audio. This may be a matter of chasing your tail.

    My scanning of her article suggests that replacing the K7DYY board with a basic preamp circuit would be a first step. Dozens of examples available on the web.
  5. W9WQA

    W9WQA Ham Member QRZ Page

    dont know what koby is but with that and a processor it dont sound like its a d104 any longer but a d104 housing !!
    K0OKS likes this.
  6. KA0HCP

    KA0HCP XML Subscriber QRZ Page

  7. KA0HCP

    KA0HCP XML Subscriber QRZ Page

    Clearly his problem would be fixed by placing the Kobitone element in a cardboard box. :) "What is a microphone?"
    W9WQA likes this.
  8. W5JAY

    W5JAY Ham Member QRZ Page

    A D104 has a presence boost around 2.5 KHz at Plus 10 DB. So look up the frequency response on that element and adjust from there with an EQ. In fact looking up a stock the d104 frequency response with good loading will give you a good idea of what you need in the long run. What is the rig you are using? That board you are using puts out a -10 DB. So be very careful if you are trying to feed a stock microphone Jack. 73 de jay..
  9. KA0HCP

    KA0HCP XML Subscriber QRZ Page

    He does not have a D104 element. He has a Kobitone element. The only thing that is a D104 is the case/stand/shell.
    W9WQA likes this.
  10. K1LKP

    K1LKP Platinum Subscriber Platinum Subscriber QRZ Page

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