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DX959 Clarifier Won't Unlock

Discussion in 'CB Radio Modifications' started by 9two7, Apr 28, 2021.

  1. 9two7

    9two7 New Member

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    Hi all,

    I have a Galaxy DX-959 Deluxe edition (the new blue display model) and I'd like to see if anyone was successful in unlocking the clarifier.

    I've attempted the modification involving the removal of jumpers JP195, JP196 and the connection of J9 pin F1 to +8V (on J6 in my case) and this resulted in the radio shifting off-frequency with the Clarifier remaining locked for x-mit.



    I see that there is an alternate mod which removes R113 and D68 in lieu of cutting the jumpers, but as far as I can see, the removal of the jumpers effectively uncouples R113 and D68, so I'd expect the results to be the same.

    Has anyone had any luck unlocking these newer DX-959 models?
     

  2. Ranch55

    Ranch55 Sr. Member

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    I have done numerous clarifier unlocks on the 959's and have not ever used the jumper from J6 ........
    It seems you may not have connected the jumper from the +8 volts to the correct J9 F1 pin.
    And a frequency alignment is required after this modification using a high quality frequency counter.
     
    9two7 and 86lidewell like this.
  3. 9two7

    9two7 New Member

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    Thanks for the reply! I suspect that the 8V which is silk-screened @ J6 is not the 8V source I was supposed to tap into. Looks like the 8V @ J14 is the one which is referenced in the instructions. Will check again and report back
     
  4. Dr_DX

    Dr_DX Well-Known Member

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    IMHO, a better way is to find a stable constant voltage source that is higher than the stock RX voltage going to the high side of the clarifier. Simply install a 10 turn trimmer pot in series and dial down the voltage until it is "on frequency". No re-alignment necessary. If you can't find a constant voltage source that is higher than the stock RX voltage, you can easily make one. Just mount a LM7809 on the side/back of the radio (heatsink) and a diode and a couple of caps will give you a nice, stable 9v source. Use the 10 turn trimmer to bring the voltage down.

    https://circuits-diy.com/9v-power-supply-using-lm7809-voltage-regulator-ic/

    This also allows you to "true up" your clarifier if it was off a bit.

    FYI - I find that taking 8v off one of the IC's in the radio many times isn't stable enough and can cause a slight shift between RX/TX. Using the LM7809, it is eliminated.

    Just my .02
    Dr_DX
     
  5. Handy Andy

    Handy Andy Do Your Research First, Then Decide...

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    From Lazarus, CB Tricks era - bless his heart...
    98VHP+Clarifier+Modification.jpg
    This is for a 98VHP - but the CONCEPT is the same,
    Break the 8 V PLL RX/TX tie-in R113, and the TX power D68...

    upload_2021-4-28_19-14-15.png
     
  6. Eldorado828

    Eldorado828 8-2-8 in the Lonestar State

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    Heck yeah, a blast from the past! Does anyone know if he's alive and well? Somewhere I've got a few printed threads from cbt where he helped me iron out some issues back then. Laz and cbt, talk about a throw back.
     
  7. 9two7

    9two7 New Member

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    Thanks guys, I picked up the 8V from J14 and it works beautifully!
     

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