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Are these pills swapable?

Discussion in 'CB Radio Modifications' started by mr_fx, Mar 5, 2012.

  1. mr_fx

    mr_fx Sr. Member

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    Ok so the wife laid a coat on my linear. 4 x 1446, I smelled BBQ, by then it was too late, 3 out of 4 of the pills where dead.

    So now I am trying to figure out what I can use to fix it.



    OK so I know that the SD1446 and the MFR455 should swap between each other. But can they swap with the 2SC2290 ? What about the 2sc2879 (I know if this worked the amp would pick up a few watts.)
     
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  2. AudioShockwav

    AudioShockwav Extraterrestrial Admin Staff Member

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    The 2290 and 2879 are larger than the 1446/455 so unless the cut outs in the board are big enough you do not have much choice.
    I would just go back with the 1446`s, and you do not have to worry about it.
    I would also change all 4 while you are in there.
    What kind of amp?



    73
    Jeff
     
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  3. mr_fx

    mr_fx Sr. Member

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    I have been told that the MS1051 pills are an alternative to the SD1446, BUT I can not find ANY info on them anywhere
     
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  4. AudioShockwav

    AudioShockwav Extraterrestrial Admin Staff Member

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    They are still larger in the case than the 1446.
     

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  5. AudioShockwav

    AudioShockwav Extraterrestrial Admin Staff Member

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    Why the opposition to the 1446 transistors?
    They are readily available and drop right in.
    Is that the Amp you are driving with the road Pro?


    73
    Jeff
     
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  6. mr_fx

    mr_fx Sr. Member

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    nope, just some just cheaper amp I recently aquired
     
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  7. psycho

    psycho Supporting Member

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    The price of the 1446 transistors is $38 a piece from RF Parts. I don't understand how laying a coat on the amp can cause the pills to go bad though. That amp would have to awful special to lay that kind of dough into it.
     
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  8. mr_fx

    mr_fx Sr. Member

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    if you lay a coat on it the heat sink can no long er do it's job of removing heat. The same way that a coat let's you retain body heat. So if it is dark in the vehicle and you are yacking away, the heat would continue to build until the pill go BOOM!!! Does that make sense now?
     
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  9. AudioShockwav

    AudioShockwav Extraterrestrial Admin Staff Member

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    Can you post a picture of the board?


    73
    Jeff
     
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  10. 9C1Driver

    9C1Driver Well-Known Member

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    Unless you were on a cross country trip most amplifiers can still handle a covered heat sink for less then an hour. So while it's possible no, does not make sense. Is this your "600 watt" 4 pill from the other thread?
     
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  11. mr_fx

    mr_fx Sr. Member

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    I was yacking and driving for close to 2 hours. So if it was not heat related then what was it? I mean the heat sink was painful to touch, I could smell the leather/burning smell. you could even see where the heat sink had changed colors around the pills.
     
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  12. psycho

    psycho Supporting Member

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    I remember when the 1446 transistors were $15 a piece just 4 years ago. The Asian countries are bleeding this country dry.
     
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  13. AudioShockwav

    AudioShockwav Extraterrestrial Admin Staff Member

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    Good Luck/

    73
    Jeff
     
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  14. 9C1Driver

    9C1Driver Well-Known Member

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    Yea........2 hours of heavy talking covered would do it covered like that the more I think about it. Is it a Palomar 400 or 450? At H&Y a new 450 with 1446 finals is 239. You will probably need to do all 4 finals and maybe even some other burnt parts. You might have 175-200 in it to get it fixed right.

    I would list it on E-bay as for parts or repair, you might get 25-50 bucks. Combine that with the repair money and you can go new.
     
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  15. psycho

    psycho Supporting Member

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    Palomars are throw away amps...use them till they blow then throw em out and buy another one.
     
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