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IRF520A

Discussion in 'Home Brew' started by Crusher, Mar 2, 2008.

  1. Crusher

    Crusher Well-Known Member

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    I was wondering, what is a clean reasonable number for an amplifier using (4) mosfets that were mentioned above?


     

  2. mackmobile43

    mackmobile43 Jock Supporter

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    100 WATTS PEP GIVE OR TAKE
     
  3. Crusher

    Crusher Well-Known Member

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    I do not have a peak at the moment, I am getting about 35-40 watts average on a Bird. Just wondering if this would be considered reasonable or acceptable.
     
  4. DIRTYWHITEBOY

    DIRTYWHITEBOY Active Member

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    Are you sure its tuned correctly? What is your bias voltage? I get 400 pep out of 16 irf-520s,works out to around 25 pep per mosfet on mine.I have my bias voltage set at 4 volts.
     
  5. freecell

    freecell Active Member

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    100WPEP = 37.5WAVG..
     
  6. mackmobile43

    mackmobile43 Jock Supporter

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    tomato, tamatoe
     
  7. freecell

    freecell Active Member

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    it's working fine Crusher.
     
  8. Crusher

    Crusher Well-Known Member

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    Dirtywhiteboy, I biased amp so that it would draw 40mA. That is 10mA per transistor. I originally biased circuit for 4.5 volts. But I found out that it is not long before replacing mosfets. I used part of design from the Ranger 94VHP. Also took a few ideas from the ARRL Amp Classics book section on mosfets using the 510 and 511's. Between the 2 this gave me a good place to start. I can't believe it only took about 160pF cap. across the output transformer. I usually am used to using something like 5 or 6 times larger.
     
  9. GRTS

    GRTS Galaxy Tech

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    What's a Ranger 94VHP?
     
  10. Crusher

    Crusher Well-Known Member

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    I think it is actually a Galaxy 94VHP. It is made by Ranger. It has 4 irf520's im the final section.
     
  11. GRTS

    GRTS Galaxy Tech

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    Thanks for that info Crusher.

    (y)
     
  12. Crusher

    Crusher Well-Known Member

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    I hooked up my LP-100 and used it in pep mode, I get right about 110Watts. Onn SSB I get about 117 watts.
     
  13. Crusher

    Crusher Well-Known Member

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    GRTS, Galaxy has a model called 98VHP. It has 8 IRF520's as final section. Might want to take a look at that as well. Going to try a few other projects with IRF550's and IRF35X series. Anyone know how I can post a pic of this project?
     
  14. AudioShockwav

    AudioShockwav Extraterrestrial Admin
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    You Have a PM.

    73
    Jeff
     
  15. AudioShockwav

    AudioShockwav Extraterrestrial Admin
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