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29 ltd audio boost,???help

Discussion in 'CB Radio Modifications' started by 1iwilly, Oct 25, 2009.

  1. 1iwilly

    1iwilly Active Member

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    hello to all
    i've read some where here but i can't seem to find the info
    on audio boost quality for a 29 ltd classic changing some caps by the audio chip.???
    or beefing up that section for better audio ouput


     

  2. Robb

    Robb Yup

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  3. 1iwilly

    1iwilly Active Member

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    i'm not looking for a power mod or variable power i lready had that done a while ago i want to boost the audio chip section not power section
    i want to make it sound room filling audio not audio coming in front of you.???
     
  4. Robb

    Robb Yup

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    There are some audio mods on these pages - if you bother to read them!
     
  5. W5LZ

    W5LZ Crotchety Old Bastard

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    From what it sounds like, you are wanting a sort of 'surround sound' affect from a 4 watt audio output audio chip. Like what I've heard out of my computer's sound card and multiple speakers? Good luck and forgetabout it. Ain't gonna happen with the components in a typical radio (of any kind, CB/ham/etc.). I would suggest looking for some sort of 'surround sound' amplifier that could be fed by the radio's speaker jack. I'd bet there would certainly be a market for such a thingy, but probably a limited one.
    At home you could probably feed the radio into your computer's sound card. Mobile, some AM/FM/stereo radios have sound input jacks.
    I think I'd give it a test run before plunking down much money for such a thingy, I have tried it and wasn't exactly thrilled with the results. But then, I don't expect 'surround sound' out of a 'communications' radio to start with, it really doesn't help anything. Oh well...
    - 'Doc
     
  6. 1iwilly

    1iwilly Active Member

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    ok i'm getting no where here let me try it this way i want to boost my audio quality to the receiving end meaning when others hear my radio like wow
    that 29 ltd driving that 1x4 your are running sounds like 5000 watts. hope this explain it better
     
  7. Robb

    Robb Yup

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    A decent mic and a great antenna -along with modest power- are going to give you that with the Cobra 29. Cobra's are good for that; just be sure that the radio is doing about 2 watts 'dead key' before it goes into your amp.

    Perhaps what you are looking for is a 'Top Gun Modulator'; which I think can be found here:
    TGT Modulator

    Is that what you mean; is that what you are looking for?
    Getting a 'big sound' isn't a difficult thing to do, so long as you have money and want to pay for it. The older tube-radios have a great sound - for instance. But some solid state radios do very well also.
     
    #7 Robb, Oct 25, 2009
    Last edited: Oct 26, 2009
  8. W5LZ

    W5LZ Crotchety Old Bastard

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    Okay, I just got it backwards, nothing new about that.
    It really just depends on what you consider 'good' audio, and that's very varuable, sort of. Basically, it means processing the audio that goes into the radio. That's another one of those 'things', probably as many answers as there are people trying to do it. It also sort of boils down to how much money you wanna throw at it. Probably the simplest/cheapest way is a new/different mic. The other end of that money spectrum is what the 'audiophiles' indulge in. Some times they spend more money than I paid for my truck+radio+who knows what else! It also comes down to how much bandwidth the resulting signal requires. I don't have any specific recommendation, I ain't going there!
    Have fun with it till it ain't fun no more!
    - 'Doc


    This is one'a my "mis-spelling" days. I'm tired of making corrections. I ain't getting graded on this, am I?
     
  9. 1iwilly

    1iwilly Active Member

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    thanks for the replies i just want that big radio sound like some of them mobilee you hear in skip
     
  10. Robb

    Robb Yup

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    Some of those guys are using the same radio you have. Maybe a Astatic D-104/M6 mic with it (nice choice - btw). But then they may also be using an 800 watt amp to get massively-modulated sound. Some of that has to do where they are as well. Eg: On top of a hill or just on high ground. Skip can work in your favor - or it can work against you. That depends upon conditions in the ionosphere and one's own location.
    Variables, variables, variables...
     
  11. loosecannon

    loosecannon Sr. Member

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    7: Change R48 to a 33K ohm resistor.

    9: change C37, and C68 to a .2 monolythic (this changes the A.F.
    response on TX)

    3: change the electrolytic capacitor by the audio IC (C42, 1000uf) to a
    3300uf, 16v


    these three mods will give you a bit wider freq response and can make you sound louder on the other end.

    add a turbo echo board and you will have the big radio sound you are looking for.
    LC
     
    NZ8N likes this.
  12. jazzsinger

    jazzsinger Bullshit Buster

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    If money is no object buy an rf speech processor,if money is tight look at an audio clipper type processor,not as effective but will give a decent boost to your audio and is much cheaper.The tradeoff will be a slight bit of distortion but very powerful audio.

    Another reasonable investment if you can find one cheap is an astatic 575-m6 microphone.Gives nice powerful audio but the trade off would be heightened background noise in a noisy environment.

    You could take the path of wideband audio and studio style processors but its costly,very few people on cb have the receiver bandwidth to benefit from it,its often overkilled by individuals who think they sound good but who are deaf to distortion,a bit like grunge rockers or heavy metal freaks.

    The other option is too undo the power mods and have the radio operate close too 100% modulation which is both loud and clear,with power mods done your radio will struggle to do 100% modulation.

    I'm not too familiar with the cobra 29 ltd but in export radios you can also keep the extra power and beef up the audio modulator/voltage regulator circuit.

    Big radio sound in my experience generally equates to crap radio sound,much better too take the path of loud but clear audio which is less stressful on the listeners ears.
     
    Tokin likes this.
  13. Shadetree Mechanic

    Shadetree Mechanic 808 On The North Side of Dover

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    This resistor swap will make any mic sound like a power mic. The Astatic 636 sounds awesome this way.

    From WWPDX
    Goldfinger wrote:

    A cool trick to get a little more gain when using a stock mic or any of the non-amplified noise cancelling mics, is to change R67, the 33 ohm resistor on the emitter leg of TR17 to a 10 ohm. When running a power mic this mod isn't needed as the 29 chassis is already a loud one when used with any amplified mic.
     
    NZ8N and tecnicoloco like this.
  14. 1iwilly

    1iwilly Active Member

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    hello to all is there a new working link to the one posted below i just tried and its not working i know the thread is a bit old thanks

     

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