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cobra 29 lx le with rfx75

Discussion in 'General CB Services Discussion' started by dxing440, Apr 10, 2011.

  1. dxing440

    dxing440 Active Member

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    :headbangWhen i ordered the radio, i had variable power and echo installed. The seller uses a (bird 43 meter) and a dummy load, and says the dk is .5w at lowest and 11w at highest, and gets 90w PEP.

    I installed this radio in my truck ,with SWR`s of 1.4 and get much different numbers.
    I used a roadtech meter and i get a dk of .5w at the lowest, and 3w at the highest with 25w average.

    I would like to buy an amp, but dont know which (wattage) to go by when i buy an amp! The (bird43) meter or my meter?

    Any advice?


     

  2. radiohobby

    radiohobby Active Member

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    If the amp input power is rated in average then use your readings and if it is rated in pep power then go by what the other guy gave you.
     
  3. loosecannon

    loosecannon Sr. Member

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    25 watts on an RMS style meter is about the same as 90-100 watts PEP, so that sounds about right, but the 3 watt max deadkey seems strange.

    your deadkey should be about the same on both meters.

    his numbers sound about right for an RFX75, but shame on him for setting the low deadkey at .5 watts. thats just stupid.


    make sure you are using a 12ga. power cord for the radio. anything less is not big enough for the RFX75.

    also make sure you are running the positive lead right to the battery itself.
    (always, always, always add a fuse right at the battery!!!)

    the negative lead should only be as long as you need it to reach to the nearest chassis/body connection.

    also, ive never heard of roadtech, but if the meter was less than 50 bucks then its probably pretty crappy.
    LC
     
  4. dxing440

    dxing440 Active Member

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    I ask him to set dead key at 2w for lowest (variable power)so i could add an amp later. But the variable all the way up should be around 11w like he says.
    I do need a new meter, it was $25 at the pilot.
    The power cord that came with the radio, i think is 14g about 6ft, but i ran 12g from the end of that wire to the battery.
     
  5. loosecannon

    loosecannon Sr. Member

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    yep, if you're using the power cord that came with the radio, its way too small.

    they are usually 18ga. dont let the thickness of the insulation fool you.

    go to ebay and buy a heavy duty 12ga. power cord. it will have fuses in both the positive and negative wires.

    yes, you do need a new meter. i would only trust that one for SWR readings, and even then it may not be very accurate.
    LC
     
  6. RatsoW8

    RatsoW8 Supporting Member, W9WDX ARC Member - WD8T

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    Is this SSB or distortion?
     
  7. dxing440

    dxing440 Active Member

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    thx loosecannon ,i will get a bigger wire

    Ratso8 this is just (am) only radio
     

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