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Cobra 148gtl Hi fi Tx/Rx mod?

Discussion in 'General CB Services Discussion' started by curlyjo, Jul 30, 2012.

  1. curlyjo

    curlyjo Supporting Member

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    Hi. Could someone tell me what the Cobra 148gtl hifi tx/rx mod is? What is it suppose to accomplish? What's involved in it? Etc. Etc.


     

  2. RatsoW8

    RatsoW8 Supporting Member, W9WDX ARC Member - WD8T

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    Here we go again. :pop:

    You might want to do a search on the forum. Lots of info/opinions/facts and tall tales on this topic.
     
  3. Robb

    Robb Yup

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    TX mods:
    Change C46 to a .2 monolithic cap.
    Change R114 to a 10K.
    Replace the big electrolytic cap on the board from a 1000mf to a 2200mf or a 3300mf (its near the large transformer) - IIRC.

    See if that info checks out - to be sure first.

    Sure that others may have more tips too.

    Think that ExitThirteen, The DB, Unit248, unit_399, slprydk, and a few others may have some answers for the TX side of this radio.

    Receive mods are in this pdf:
     

    Attached Files:

    #3 Robb, Jul 30, 2012
    Last edited: Jul 30, 2012
  4. Eastside

    Eastside Well-Known Member

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    You must be a different Curly that I was talking to on another radio forum who said that he did the hifi mod on his radios?
     
  5. dave457

    dave457 Well-Known Member

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    Goldfinger 148Mod

    Tx side

    C46 Change to 2.2uf mylar/polyester film or non-polarized electrolytic
    C101 Change to 1.5uf tantalum 16 to 50 volt
    C102 Change to a 910pf ceramic disc
    C104 Change to 2.2uf tantalum 16 to 50 volt
    C108 Change to 1uf to 2.2 uf tantalum 16 to 50 volt
    I found that if you have a very deep voice start with 1uf on C108
    and work up if need be.

    If you need more highs on tx Change C 105 to .001 to .0001uf mylar/polyester film The smaller you go the more highs you get.

    RX

    C71 Change to 1uf mylar/polyester film or non-polarized electrolytic

    C75 Change to .001 to .0001uf this will give you more highs on rx
    optional
    C76 Change to 2.2uf mylar/polyester film or non-polarized electrolytic

    C182 Change to .001 to .0001 for more highs on rx and tx
    optional
    C183 Change to 2.2uf mylar/polyester film or non-polarized electrolytic

    C187 Change to 2.2uf mylar/polyester film or non-polarized electrolytic

    With C75 and C182 you can start with no Change to them, then if you feel you want more highs then change them out
     
    2 people like this.
  6. psycho

    psycho Running a special on our rooms!

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    Now we need to find the Cobra 148 Surround Sound mod.
     
    skiman1, tuner, tecnicoloco and 3 others like this.
  7. tecnicoloco

    tecnicoloco Tweaknician in Training

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    What about a Cobra 148GTL THX :D
     
  8. Watergate

    Watergate Well-Known Member

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    The 148 Dolby mod I could go for. ;)
    But THX has to be certified by George Lucas, and after seeing what he did to Indiana Jones, he's not getting anywhere near my radio.


    Sent from my DROIDX using Tapatalk 2
     
    1 person likes this.
  9. jazzsinger

    jazzsinger Bullshit Buster

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    :LOL::LOL::LOL::LOL::LOL::LOL: hifi audio on a cb,
     
  10. Eastside

    Eastside Well-Known Member

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    Hi Fi is really a bad name for the mod....the mod is supposed to make the radio wider banded....wide band mod would be more correct I suppose.....weather it truly makes the radio wider banded is debatable.....but I have heard radios that have had it done and they do sound like they are wider banded allowing more lows and highs to pass? :)
     
  11. dave457

    dave457 Well-Known Member

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    No need for THX or surround sound if you have good quaility head phones :)
     
  12. psycho

    psycho Running a special on our rooms!

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    Not to narrow down my age but when I hear the word "Dolby", I think of "She blinded me with science".
     
    tuner likes this.
  13. 9C1Driver

    9C1Driver Sr. Member

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    If you do decide on doing this to your Cobra you will have to run it with some rack gear as well. Then you will have to make sure you have the EQ all dialed in just right. After that your 300 dollar heil mic will need to be dialed in with the system and your voice.

    When I hear these guys on 11m running all this stuff maybe 2 out of 10 sound good. The rest have a mono tone drone or nasal sound. I suppose those running a Kenwood or Yaesu radio can hear the difference better.

    Hmm. here is an idea. Since we are on 11m and your Cobra was made to talk there why not give it a correct tune and alignment. Add a nice desk mic, maybe a small AB amplifier, and the best and tallest base antenna you can and be done with it.
     
  14. curlyjo

    curlyjo Supporting Member

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    Thanks for all all thy info!
     
  15. len sandora

    len sandora Member

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    tx mod

    I need more lows on tx Thanks Len
     

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