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Silicon Carbide MOSFETs?

Discussion in 'CB Radio Modifications' started by nomadradio, Mar 27, 2019.

  1. nomadradio

    nomadradio Analog Retentive

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    So, who's gonna be the first to try some of these as RF amplifiers?

    SiC MOSFET transistors are the next big thing in power-supply design. The one in the data sheet below is meant for pretty high voltages.

    But the capacitances look really low, and the switching speeds pretty high.

    Haven't even checked the price, yet.





    Looks kinda promising.

    73
     

    Attached Files:

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  2. sonoma

    sonoma Sr. Member

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    gate voltage shows typ 2.5 and max 4.0 which does not look bad but the size shows it to be a T0 247. a little large for a final for most radios unless I am missing some thing in looking at the spec sheet.
     
  3. nomadradio

    nomadradio Analog Retentive

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    Just thinkin' out loud.

    73
     
  4. loosecannon

    loosecannon Sr. Member

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  5. loosecannon

    loosecannon Sr. Member

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    some pics from that project:
    [​IMG]

    [​IMG]

    [​IMG]

    LC
     
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  6. Redbeard U812

    Redbeard U812 Sr. Member

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    all that is missing is a Jacob's Ladder
     
  7. Redbeard U812

    Redbeard U812 Sr. Member

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    Albeit the size could it be used to replace a 2sc1969?

    I am not the master techs you's guys is. I just have a POS 148gtl needs attention and resourcing is all I can do. I follow you's guys trying to learn. Though I am in the weeds I have benefited with knowledge from this place.
     
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  8. loosecannon

    loosecannon Sr. Member

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    redbeard,

    your best bet for repairing that final is to either buy a real 2SC1969 or you can convert it to an IRF520 mosfet.

    exit13 wrote up an excellent article on how to convert the old school 8719 and 858 radios to mosfets.

    it's here on the forum somewhere.
    LC
     
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  9. Redbeard U812

    Redbeard U812 Sr. Member

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    Yes, I read that one thoroughly. Twice. RF has the 1969's for $17. Just exploring.
     
  10. Tallman

    Tallman W9WDX Amateur Radio Member, KW4YJ EXTRA class

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    Also needs Igor and a kite in a thunderstorm.
     
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  11. Redbeard U812

    Redbeard U812 Sr. Member

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    [​IMG]
     
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  12. Handy Andy

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

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    Although you have a working prototype, that's great, but remember the issue of "carbon" doping versus the other elements like Boron or Gallium - Hole - Donor principle.

    They make the part able to be "shut off".

    Carbon doesn't have the graces of having that property.

    It wants to keep the part "on" all the time - electrons will have no where to fill in what's left - they have to wander across to find equilibrium.

    What is worse is there lack of rectification ability without forming a PN junction to form a barrier to make this work.

    It's the "fall times" that make this worrisome for making Amps work without generating a meltdown similar to what the Fukushima plant experienced.

    Now, before anyone screams - "The do it with LED" - remember that the junction itself is what emits the radiation - as you work thru the process you'll see that making Diamonds in the lab is a far easier way to make money than to re-create that which was formed in nature on a more gradual - volcanic - way using Oxygen, Sulfur or Nitrogen to generate the various effects as catalysts on the two materials.

    But, "As Seen On You Tube" - they're working on it.
     
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  13. nomadradio

    nomadradio Analog Retentive

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    Pretty sure the amp in the pic above is for 7 MHz. All switchmode MOSFETs will have an upper frequency limit. The bigger the part, the lower that frequency tends to be.

    The numbers to watch in the specs are rise time, fall time, turn-on time and turn-off time. Faster is better. Means a higher max frequency.

    The Littelfuse part in the spec sheet above is faster than the specs shown for the IRF520.

    That was what got my attention.

    73
     
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