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Cobra 2000gtl Audio mods.

Discussion in 'CB and Export Equipment and Accessories' started by GunSlinger338, Oct 28, 2008.

  1. GunSlinger338

    GunSlinger338 Active Member

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    I recently picked up a Cobra2000 GTL..Brand New in the BOX !! . going to use it primarily for local every day talking..
    Would like to get it capable of transmitting better quality audio on AM ...
    Any one know any Mods. to widen the transmit audio range????????


     
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  2. Moleculo

    Moleculo Administrator Staff Member

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    There was a thread here, but I couldn't find it. This was posted a while back as a complete set of mods for audio:

    Also applies to:
    Cobra 148GTLF
    Cobra 2000GTL
    Undien Grant XL
    Uniden Grant LT

    1. Carrier Adjustment: VR10. If lower carrier is desired, change R196 near VR-10. Try about 270 ohms.
    2. Change R114 to a 10K, and C46 to a .2 monolithic, this will widen up the audio on AM.
    3. The AMC is TR-26. You can remove it, and still have good results on AM, the ALC for SSB is not effected by this. If you don't want the AMC disabled, leave it. The other way to disable the AMC is cut R131. Check both to restore AMC from previous mods.
    4. If extra frequencies have been added, perform the following to widen up the band pass filters to recover lost power at the highest and lowest frequencies: C163 - 4pf, C41 - 3pf
    5. R180 - Jumper it. This brings up the gain of the TX mixer.
    6. IC TDA6130 - Pin 12 to ground through 100 ohm resistor. Upper left, pin 14 = ground.
    7. Remove the AM regulator, (usually a 2SC1419) and replace it with a 2N6487.
    8. C174 - remove, add 1000uf electrolytic. connect POS to base of yellow wire next to it. If the yellow wire is too far away, it might be easier to connect the POS leg to the leg of the AM regulator closes to the back of the chassis via the bottom of the radio.
    9. For 148F, change C18 to a 1000uf electrolytic, 16V
     
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  3. GunSlinger338

    GunSlinger338 Active Member

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    Thanks....... I too was unable to find it in other posts
     
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  4. KB1TPX

    KB1TPX W9WDX Amateur Radio Club Member

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    #4
  5. Number15

    Number15 Active Member

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    Hey gunslinger how much did u pay for that 2000??????
     
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  6. super20dan

    super20dan Member

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    only and idiot would mod this mint radio-why do you think ebay is loaded with broken 2000 cobras
     
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  7. GunSlinger338

    GunSlinger338 Active Member

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    400$ and some change
     
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  8. KB1TPX

    KB1TPX W9WDX Amateur Radio Club Member

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    #8
  9. GunSlinger338

    GunSlinger338 Active Member

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    LOL.... this must be the guy that was out bid at the last sec.

    Sorry Guy
     
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  10. 9C1Driver

    9C1Driver Well-Known Member

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    With such a nice, origional mint radio I would have a qualified tech go through it. A nice tune and alignment should do the trick. Combine that with a D104 desk mic and you will be wall to wall.
     
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