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Dave Made straight 4

Discussion in 'Amplifiers' started by TIN_CAN, Mar 19, 2021.

  1. TIN_CAN

    TIN_CAN Sr. Member

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    I picked up a Dave Made 4 pill, looks to be an older one by looking at the front of it, in good physical condition with original Toshiba 2879's. But from what I have found online is that DM amps were class C only, but this looks to be set up for ssb? anyone confirm this. Even has a blue pimped out fan that is really quiet. Was planning to drive this with around 50W pep and run it in my f150.

    Cheers!

    [​IMG]

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    [​IMG] [​IMG]


     
    Shadetree Mechanic likes this.

  2. 9C1Driver

    9C1Driver Sr. Member

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    It's probably still class C, they just added a SSB delay or someone did anyway. It will still sound rough on SSB.
     
    TIN_CAN likes this.
  3. DoctorAudio

    DoctorAudio Active Member

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    Might want to take the wirewound resistors off of the splitter/combiner and feedback and replace them with metal film. Inductive resistors here are a no-no.
    It is still class C.
     
  4. TIN_CAN

    TIN_CAN Sr. Member

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    Thanks, just confirms what I thought ...that its still a class C amp.
     
  5. nomadradio

    nomadradio Analog Retentive

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    Consider that adding bias for sideband may also lead to stability trouble.

    Might, might not. But this amplifier has one design goal: max wattmeter reading.

    Stability is not high on the priority list.

    Then again, it you mod it for sideband bias and it gets squirrelly you can always unhook that stuff and put it back to class C.

    73
     
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  6. TIN_CAN

    TIN_CAN Sr. Member

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    Thanks Nomad I planned on using this with a ssb radio but if it sounds to much like crap on air it will go in the closet, I paid $250 Canadian, I guess I have 4 matching toshibas for back up for my palomar 6500R if they ever fail.
     
  7. S&W357

    S&W357 $upporting Member N.C. WDX-556

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    I've got a somewhat similar Dave Made amp. This one has only two Toshiba SC2879 red dots but it is a base amp with an iron core transformer. I use it on SSB with a Anytone AT-6666. I get good reports on audio from both locals and on DX.

    Clean? I dunno. :barefoot:

    upload_2021-3-22_19-41-17.jpeg
     
  8. Shockwave

    Shockwave Sr. Member

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    This is important. Especially in the negative feedback circuit which, may not even be functioning at all with wire wound resistors. RF sees this as a choke, only with even more resistance due to the wire used. Instead of looking like 100 ohms, it could be 10 times higher at RF.
     
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  9. TIN_CAN

    TIN_CAN Sr. Member

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    I heard you with that 2 pill sounded fine to me.
     
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  10. Shockwave

    Shockwave Sr. Member

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    The way things are going, soon the ammo in the background, may be the most valuable thing in the photo. That wasn't meant to take anything away from the amplifiers either.
     
  11. snippits75

    snippits75 Well-Known Member

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    You got that right!
     
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  12. lonestarbandit

    lonestarbandit 4-2-9 Central TX

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    LOL
     

    Attached Files:

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