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d&a mdx-200 or pdx-400 owners manual

Discussion in 'Amplifiers' started by 313inthegarden, Mar 6, 2011.

  1. 313inthegarden

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    Hello guys, is it possible to still get the owners manual for these amplifiers anymore. i've done a lot of searches but have found very limited info on these amps. any direction or help would be greatly appreciated. thanks, 313


     

  2. mackmobile43

    mackmobile43 Jock Supporter

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    Inquire here.

    Kens

    And here
     
  3. 313inthegarden

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    I've seen both of these. ken emailed me back and he only has the schematic and qsl.net only has the pics. any other suggestions? thanks, 313
     
  4. mackmobile43

    mackmobile43 Jock Supporter

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    Sorry no
     
  5. Twobits2

    Twobits2 New Member

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    I'm also looking for the schematic for the MDX200 amplifier. I want to convert it to 6 meters
     
  6. nomadradio

    nomadradio Analog Retentive

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    Best I can recall, the only "manual" that D&A sent with these was a single 8x10 page of conversion instructions. How to convert it from a crystal-controlled ham CW transmitter back to the linear it was meant to be.

    This was a dodge to get around the FCC rules banning CB linears.

    Never have seen anything more than the schematic for it.

    73
     
  7. BJ radionut

    BJ radionut Supporting Member

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    https://www.eham.net/ehamforum/smf/index.php?topic=20713.5;wap2

    Info you might glance at in regards to sweep tube usage on 6m.
    I had a drawing for a pair of 6LQ6's on 6m but for life of me can't find it. One thing to remember is the output of say a 6LQ6 on 10 meters, using the same tube on 6m output will be reduced by 30%-50%...so a pair of them on 6m is pushing it at 200w PEP...the Knightkit T175 amplifier used that very circuit...That manual should be on-line.
    I think by the time you spend converting the drive circuit(or scrapping it! MHO) plus modifying the final stage of that D&A amp to 6m...your reaching for the stars IMHO.
    Stability is going to be a real issue, let alone time invested for any reasonable output.
    Best sell it as-is and use $$ for a true 6m amplifier. The power supply could be used with mods for say a Russian GI7B tube or the old 4cx250b in GG, and could work well, just to many things would need to be addressed with amp as-is to make it play.
    Good Luck
    All the Best
    Gary
     
    #7 BJ radionut, Apr 30, 2018
    Last edited: Apr 30, 2018

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