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Sears Road Talker mobile Carrier on SSB

Discussion in 'CB and Export Equipment and Accessories' started by Anthony R Belle, Oct 12, 2018.

  1. Anthony R Belle

    Anthony R Belle New Member

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    MY Sears Road talker places a carrier on SSB More on LSB then USB. I hear a hum from the speaker when I transmit. Any Ideas?
    Thanks!


     

  2. nomadradio

    nomadradio Analog Retentive

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    First thing I want to know when this happens is what an external counter reads.

    I always have a counter in line with the radio's output. If the frequency is almost the same as the channel frequency it shows in AM mode, that points to the radio's sideband modulator and audio circuits.

    If the frequency is way out in left field, not anywhere near your channel frequency this means the radio's final and/or driver section is oscillating. When this happens, the frequency of the carrier is not controlled by the channel selector.

    Loose ground screws around the edge of the main circuit board can do this.

    And it could be that the power supply has a problem when the transmitter loads it down. If the power supply has what they like to call "hum", or AC ripple, this can get into the radio's mike-audio circuit.

    Do you have another radio you can use to listen to this one and see what you hear when the Roadtalker transmits on sideband?

    73
     
  3. 9C1Driver

    9C1Driver Sr. Member

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    When you check this I would also not use a power mic and turn the mic gain all the way down. Sometimes when you key up but don't speak on SSB background noise can appear as a small carrier.
     
  4. Handy Andy

    Handy Andy Do Your Research First, Then Decide...

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    "A hum from the speaker when I transmit" - this could get interesting.

    Got any history on that radio?

    Like...

    Was Dads, resurrecting it from an cleaning out an attic... (Family Heirloom)

    OR

    Found on eBay so I bid on it...(Wanted a challenge)

    Or something g even more exotic like...

    Bought this old Chevy and right underneath the seat was this...(Police are on their way..)

    To help us help you, is there something more - like even a model number?
     
  5. Anthony R Belle

    Anthony R Belle New Member

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    I changed power supplies and no power mike, No difference, I guess a repair shop is in order.
     
  6. nomadradio

    nomadradio Analog Retentive

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    If you lack any of the tools to pin down the problem, that's probably the next step.

    73
     

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