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RM Italy stinger on a variable pot

Discussion in 'Amplifiers' started by TruckerKevin, Jul 9, 2019.

  1. TruckerKevin

    TruckerKevin Active Member

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    can this be achieved? Put my 100 watt stinger board on a variable pot to adjust the rf power?




    Just a curious project
     

  2. Tallman

    Tallman W9WDX Amateur Radio Member, KW4YJ EXTRA class

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    Just install it in a radio that has variable power.
     
  3. TruckerKevin

    TruckerKevin Active Member

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    That’s what I was wanting to do. I have an old Saturn galaxy that has issues and we’ve never been able to get more than 10 watts out of.

    My thought was to put the stinger board inside it with a good cooling solution and maybe some shielding for rf, and put it on a pot to adjust it.

    Just wasn’t sure if the stock pot would handle 100 watts. Should I just hook it up to the power wire of the amp?
     
  4. Tallman

    Tallman W9WDX Amateur Radio Member, KW4YJ EXTRA class

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    No more than 1.5 watts input to the stinger board.
     
    357magnum likes this.
  5. TruckerKevin

    TruckerKevin Active Member

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    That’s about what the radio dead keys at
     
  6. AudioShockwav

    AudioShockwav Extraterrestrial Admin
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    You use the power adjustment on the radio to control the drive to the stinger board.
    You do not put the variable inline with the power wire to the amp.
    I don't know how stout the power supply is in the old satern radios or if it will handle the extra load.

    Make sure you turn the power adjustment down inside the radio so that even if you turn the variable full up on the radio it will not over drive the add on amp or you risk smoking it.


    The stinger board should be mounted on some kind of heatsink with a small fan on it.
    And it would not hurt to use something to shield it from the radio.

    I had one of the old stingers with the mrf455 in a cobra 29 and it worked well after I made a little aluminium cover for it to shield it from the guts of the radio.
    I used a heatsink and fan from a video card to keep it cool.
    Not bad for a stealth setup but it never got close to 100 watts output.
    73
    Jeff
     
  7. nomadradio

    nomadradio Analog Retentive

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    And you'll need a power supply to run the stinger.

    Built-in power supply might croak under the added load.

    Mobile radios only have this problem when running indoors from a DC power supply.

    73
     
  8. TruckerKevin

    TruckerKevin Active Member

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    So that must be the reason why my power supply was cobra heated up the other day when I was turning the radio up with the stinger board inside the house. Why is that? What significance does the DC power have to do with heating up a mobile radio ?

    I have already replaced the power supply in the Saturn with a switching type
     
  9. 999

    999 Well-Known Member

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    How many amps is the new supply in the Saturn? If it's 30 amps it could be cutting it close on SSB with the stinger on. I'd want 40 amps just to have some head room.
     
  10. TruckerKevin

    TruckerKevin Active Member

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    It’s a 30 amp
     
  11. TruckerKevin

    TruckerKevin Active Member

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    I’m curious as to why this happens? I had a new cobra 29 that smoked a power supply when I tried using it as a base.

    The cobra 29 in this conversation I’m using now the power supply started getting hot and smoking but I shut it down quick enough.

    What significance does having it on a power supply in my house have to do with it? And is there anything that I can do to prevent it?
     
  12. Tallman

    Tallman W9WDX Amateur Radio Member, KW4YJ EXTRA class

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    Where do you think the watts from the stinger come from? There are two ways to make power, High current low voltage, or High voltage and low current.
    If want your watts you have to feed it.
     
  13. TruckerKevin

    TruckerKevin Active Member

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    Well the first cobra that I’ve burned up the power supply on didn’t have any power running to it I didn’t have a stinger board connected to it. It just didn’t like being hooked up in the house
     
  14. Tallman

    Tallman W9WDX Amateur Radio Member, KW4YJ EXTRA class

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    Some times power supplies just die. New or old they all die.
     
  15. TruckerKevin

    TruckerKevin Active Member

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    Nomadradio said “Mobile radios only have this problem when running indoors from a DC power supply. “

    What makes the indoor dc power supply any different to make it a problem verses being in a vehicle? I hope you can see my question. The way I read his post, there is something leading me to believe that running them from a DC power supply is different than running them from a vehicle
     

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