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Is a Soft Key needed?

Discussion in 'Amplifiers' started by Crambone, Jul 23, 2021.

  1. Crambone

    Crambone Well-Known Member

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    I'm going to use a Kenwood TS830S with a Heathkit SB-200 do I need a soft start? If so what one is available and from where?



    73’s KB2LMN
     

  2. Justme

    Justme Sr. Member

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    When i rebuild my Heathkit SB-1000 i put a soft start in it as well.
    Reason? i don't like the thump it sometimes made switching it in and sometimes taking out the group it is connected to 16 amps at 230 volts.
    Automatic fuses are really fast......;)
    And i didn't like the blast of rush in power for the electronics, tube ( new 3 - 500ZG) transformer etc.
    So, just a 1 second delay to charge the electrolites and start up then it switches over.
    I know it can handle it without, but it gives some re assuring things don't get blasted .
     
    NZ8N and tecnicoloco like this.
  3. nomadradio

    nomadradio Analog Retentive

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    The first place I would normally send you for a soft start module is Harbach Electronics.

    Just one problem. His basement flooded and wiped out his business operations. Says he'll be back, but doesn't say when.

    Even a half-second delay helps a lot. Remember that the longer the delay, the bigger the limit resistor has to be. It can get only so hot in a half second. But the longer the delay, the bigger it will have to be.

    We have used a few from chinabay, but that's a crap shoot. I'll see if I can come up with a reliable alternative.

    73
     
    tecnicoloco, NZ8N and wavrider like this.
  4. Crambone

    Crambone Well-Known Member

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    Anything else I should do to the SB-200 prior to using with TS-830S?
     
  5. BJ radionut

    BJ radionut Supporting Member and 6m addict

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  6. nomadradio

    nomadradio Analog Retentive

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    Cool link. Thanks. But probably not necessary. Seems to me the amplifier keying jack on the TS830 connects to the unused side of the antenna changeover relay. A relay big enough to carry the radio's full RF output will tolerate the SB220's stock relay voltage just fine with no need to buffer it.

    Patch cord alone should be all you need for that radio. And most newer-model ham HF transceivers would probably croak if you tried this.

    73
     
  7. Crambone

    Crambone Well-Known Member

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    Thanks for the input guys!
     

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