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Uniden PC78LTW Service Manual?

Discussion in 'General CB Services Discussion' started by Hamin' X, Dec 3, 2006.

  1. Hamin' X

    Hamin' X Active Member

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    I have acquired a Non-working Uniden PC78ltw. Anyone know where I can get the service manual? From searching, I would say that this is similar to one of the Cobra 29 models. Anyone know which one? Thanks for any info.

    Rich


     
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  2. Hamin' X

    Hamin' X Active Member

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    Anyone?

    It looks like the schematic for the 29 LTD matches up with what I see on the 78's board. Any major differences?

    Rich
     
  3. Switch Kit

    Switch Kit Active Member

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    you can get one from uniden for 5 dollars. manuals
     
  4. Hamin' X

    Hamin' X Active Member

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    A bargain at half the price, since you can download the "owners" manual for free. I need the "service" manual. Thanks anyway.

    Rich
     
  5. Switch Kit

    Switch Kit Active Member

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    you said it wasn't working ? How so isn't it working ? Doesnt fire up ? No tx are RX ? both ? and yes it is simlar to the 29.
     
  6. Hamin' X

    Hamin' X Active Member

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    Lights up. No transmit, or receive. Have tried mic on another uniden 4 pin and it works fine.

    Rich
     
  7. Switch Kit

    Switch Kit Active Member

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    if you try the PA and you get audio , that will mean the audio chip is good (use exsention speaker ) , those radios are made tough ! Do you get anything from the weather board ? You said it fired up , did you look down from where the power goes in there should be a little black diode , sometimes they will look burnt and other times they won't (that's the protect diode in case it is hooked up backwards without a fuse in line ,you can take the diode out without replacing it and see if the radio comes alive, but do not hook the radio up backwards after you do that , always best to change the diode to a new one for yours and the radios protection ) you can also look on the bottom of the board where the power comes in ,I've seen them fried so bad that some of the traces will be burnt as well breaking off needed connections , you can just carefully re attach the traces if need be. What would be left would be to change the final and the driver which would be be fairly cheap to do , a 2266 and a 2314 driver will work for you or anything else equal to those. As I said , those radios are tanks , and I would guess to say that it wasn't anything to serious that can't be fixed. Good luck to you.
     
  8. Hamin' X

    Hamin' X Active Member

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    SK, you obviously are not reading my posts correctly. I really would like to know if I can use the schematic and block diagram for a 29LTD to trouble shoot a PC78ltw. Or, can someone steer me to a place to purchase the service manual for the 78?

    Rich
     
  9. Switch Kit

    Switch Kit Active Member

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    IM fairly sure I read you right , I was attempting to try and help you here , I'll try and keep that in mind for any further next times. Good luck to you. Peace
     
  10. Hamin' X

    Hamin' X Active Member

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    Sorry, I was having a bad day.

    The protection diode is fine, because the radio lights up. There is internally generated audio noise, but not receive, or transmit of RF. I suspect a problem in the LP filter section, but cannot see any cold solder joints, or other visible problems. I really could use a schematic and block diagram for this radio.

    Again, sorry for the abrupt reply and thanks for your help.

    Rich
     

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