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Thread: Cobra 29 variable power mod problem.

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    Cobra 29 variable power mod problem.

    My variable power mod is jumpy. It'll jump from 0 to 2w going up. and then going down it'll jump from 1 to 0w. I've tried 2 separate kits. they both do the same thing. What's the deal? Anybody got a clue?
    I'm as crazy as my meds let me be...Sometimes that's a little overwhelming for people...LOL

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    not sure what you are using to do the the variable power adjustments on your radio. this is the one I have used for years on the 29 radios and it worked good.

    http://www.cbtricks.com/radios/cobra...en_Var_Pwr.pdf

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    Quote Originally Posted by sonoma View Post
    not sure what you are using to do the the variable power adjustments on your radio. this is the one I have used for years on the 29 radios and it worked good.

    http://www.cbtricks.com/radios/cobra...en_Var_Pwr.pdf
    Tip-120 transistor, 470uf 25v cap, and a 100-ohm 1/4w resistor.And a 1000 ohm potentiometer.
    The 520 mosfet shouldn't hurt its function, should it?
    Last edited by T-I-N-Y34; 06-30-2018 at 07:43 AM.
    I'm as crazy as my meds let me be...Sometimes that's a little overwhelming for people...LOL

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    I have put this set up in a few mosfet versions with no problems.

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    here is a guy in Texas selling the tip-120 trans. the parts are very cheap to put this together with.

    https://www.ebay.com/itm/10-Pack-TIP...oAAOSwU4FaHdKs

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    Quote Originally Posted by sonoma View Post
    here is a guy in Texas selling the tip-120 trans. the parts are very cheap to put this together with.

    https://www.ebay.com/itm/10-Pack-TIP...oAAOSwU4FaHdKs
    I've put this kit in twice in the same radio and both did it.
    The first kit the pot was bent And I though that might be the problem. But it wasn't.

    https://www.ebay.com/itm/Cobra-29-Or...gAAOSwb~Ja3Oid
    I'm as crazy as my meds let me be...Sometimes that's a little overwhelming for people...LOL

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    those kits on ebay has some smaller parts in them that do not hold up well at times. not knocking the mods they sell but you can build your own for about 2 to 3 dollars and it will be more robust in my opinion. I have never had one fail so far and a lot of my repair shop buddys use this one also. you can buy the 1000 ohm pots from one seller for 4.99 for 5 and that includes shipping. you see the price for 5 tip-120 trans and the caps are cheap also with the resisters 2.50 for 100 from a seller I use and that again includes shipping.

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    Quote Originally Posted by sonoma View Post
    those kits on ebay has some smaller parts in them that do not hold up well at times. not knocking the mods they sell but you can build your own for about 2 to 3 dollars and it will be more robust in my opinion. I have never had one fail so far and a lot of my repair shop buddys use this one also. you can buy the 1000 ohm pots from one seller for 4.99 for 5 and that includes shipping. you see the price for 5 tip-120 trans and the caps are cheap also with the resisters 2.50 for 100 from a seller I use and that again includes shipping.
    This is whats in this kit.
    • Tip-120 transistor, 470uf 25v cap, and a 100-ohm 1/4w resistor.And a 1000 ohm potentiometer.
      AND... He sent me a link to a video of it working on one of his radios. And he said my wifes name in the video. So I know it works like it should it's got to be in my radio.


    Plus, If the guy's kits were crap the hundreds of people that have bought them would kill his feedback. I just don't get it there's nothing in the kit I haven't seen in a dozen or more setups. I just don't get it...lol
    Last edited by T-I-N-Y34; 06-30-2018 at 09:14 PM.
    I'm as crazy as my meds let me be...Sometimes that's a little overwhelming for people...LOL

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    But it's not that big of a deal anyway. I can set it for 1w if I run an amp so it's all good.
    I'm as crazy as my meds let me be...Sometimes that's a little overwhelming for people...LOL

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    if the kit you are getting has what you say it has you should not have a problem. most of the kits have a 2sc945 trans in them and are not made to hook up in the locations as it should.
    now Tiny do not put words in my mouth I never said he was selling crap. all I said was some sellers are using smaller parts than what I sent you a link too. even some are using a small VR that you have to open the radio to adjust them.

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