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Thread: DT40 scanner problems

  1. #81
    Join Date
    Dec 2006
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    Essex, UK
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    Default

    the idea was so some of the back of the psu and amps were heat sinked as well.
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  2. #82
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    Dec 2006
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    Pflugerville, TX, USA
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    Those big blocks of aluminum will do a great job of removing heat from the scanner amps at first. But due to their large mass to surface area ratio they aren't going to be effective at getting rid of the heat. After leaving your scanning running for awhile the blocks will reach some steady state temperature that is probably quite a bit higher than you would hope for. At that point they are pretty useless as heat sinks. If you replaced those 1"x1" bars with 1"x1" hollow tubing you will probably end up with better results. Not only that but it would make your scanner weigh less.

  3. #83
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    i have drilled some holes in the alum blocks, so there not totally solid
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  4. #84
    Join Date
    Jan 2006
    Location
    Charleston, SC
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    2,147,489,446

    Cool

    Andy, they're as good as solid. Drilling a couple holes doesn't change the surface area by much at all. Dave and Gary are right; you're doing more harm than good with those large blocks of aluminum. Better to remove them completely and replace with a 3/16 inch thick sheet.

    Actually, you probably don't need any more heat sinking at all. The amps work just fine when they're bolted to a metal base. (They even work OK with no external heat sinking; they just run a little warmer.) If I were you I'd remove the blocks and leave it at that.

    Adam

  5. #85
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    Quote Originally Posted by Pangolin View Post
    Hi guys,

    The notch filter most likely has nothing to do with this problem. In fact, yes, I recommended that Jain remove the notch filter (and also perform about a half dozen other changes). Sadly (amazingly?) he did not take my advice on anything I recommended... I know this because another PL member recently had Jian send me a set of DT-40 directly to Pangolin, to be modified and paired with a FB3 system we will soon be shipping.

    I have done the mod to a number of PL members' DT-40 scanners. For those interested, you can see a brief report I made here:
    http://www.pangolin.com/_Files/DT40.pdf

    I have kept that report private, and sent it to Jian on September 25, 2007, so that he can improve his scanners (not only for himself, but also for all of his users and people purchasing scanners from him). Clearly this is no financial benefit to Pangolin. We just like to have equipment out there that is as good as possible...

    As you can see, my mod actually makes the DT-40 easier to tune. Without the proper equipment (which almost nobody has), it is impossible to tune a notch filter. So... get rid of it! Also, Jian has unfortunately proven time and time again that he is unable to properly tune high frequency damping so... get rid of it!! By removing components, reliability is actually increased. So these changes not only improve performance but also reliability too...

    Anyway, andy_con, if you want to send your scanners to me, we'll crank them up on the DSA and get them tuned up like clockwork.

    Best regards,

    William Benner
    Pangolin have my scanners
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