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MegaWatt vs. Chinese Imitation 30 amp switching power supply comparison

Discussion in 'Product Reviews' started by Moleculo, Mar 19, 2015.

  1. dave457

    dave457 Well-Known Member

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    Dude, they make fans that are literally silent! and I don't think a fan running all the time when the unit is just on or pulling amps will hurt anything other than needs a good dusting out every now and then


     
    222DBFL likes this.

  2. N0NB

    N0NB Active Member

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    Can you recommend a way that doesn't void the warranty, DUDE?
     
  3. Old_Crow

    Old_Crow Active Member

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    Been using them for a few years now and I added a large 4M cap as a filter and no problems. I got it from a auto stereo shop.
     
  4. Megawatt

    Megawatt Contributing Site Sponsor

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    The fans run all the time to eliminate heat cycling. The constant heating and cooling of the internal parts of a power supply is what causes early failure. The problem is the power supply needs 25 CFM to keep it cool so the movement of air is what you are hearing. The fan manufacturer and my db meter both read 30 db at 3 feet with the fan blowing away from the meter. Feel free to open the case and change the fan if you can find one quieter but 30 db is the quietest double ball bearing fan I can find that moves 25 CFM. I know this thread is old but I didn't see it before.
     
    #109 Megawatt, Apr 20, 2017
    Last edited: Apr 20, 2017
    jwilkers and LeapFrog like this.
  5. jwilkers

    jwilkers Member

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    Fan doesn't bother me at all :) Tells me it's working........ working great for 5 years and counting now.
     
  6. Megawatt

    Megawatt Contributing Site Sponsor

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    Yes, some people are super sensitive to noise. 30 db is equal to leave rustling sound-wise. I have a video of four S-700-12 power supplies running in parallel on my website. Its a great way to compare my voice to the sound of four units running together before you buy. One power supply is a lot quitter than four running together too. If anybody knows of a 60mm X 60mm X 25mm 12 volt 25 CFM fan than is quieter than 30 db please tell me about it.
     
    BBI and 2RT307 like this.
  7. wavrider

    wavrider W9WDX Amateur Radio Club Member

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    I am using two of the 50 amp in parallel
    PS are about 2 1/2 feet from my rig
    Never ever one complaint about back ground noise from the fans.
    I do not hear the fans at all
     
    222DBFL likes this.
  8. N0NB

    N0NB Active Member

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    For all of those that have no problem with the fan noise, mine is listed for sale in that section. It has been in the box all of the time since I noted my experience in this thread. It is essentially brand spankin' new.
     
    wavrider likes this.
  9. 2RT307

    2RT307 Sr. Member

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    I have a ham friend that just bought one, and he seems really happy with it.

    73,
    Brett
     
  10. Riverman71

    Riverman71 Well-Known Member

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    I have the 30 amp version and love it. Purchased it directly from the Mega Watt website (clicked on their ad on this site.) These are real bargains and service is great. Shipped the same day as ordered.
     
  11. jon666

    jon666 Well-Known Member

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    i love the 30 and 40 amp supply's
    but the 50 is to dam loud for my shack. its brand new in the box. if anyone is interested pm me your offers. ill never use it. thanks
     
  12. Megawatt

    Megawatt Contributing Site Sponsor

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    Feel free to change the fan without voiding the warranty. The only thing I ask is to give me the make and model number of this 25 CFM quite fan so I can use it. The only way I have found to make it quitter is to install less CFM fans. This will increase heat and reduce life.
     
    Tallman likes this.
  13. Tallman

    Tallman W9WDX Amateur Radio Member, KW4YJ EXTRA class

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    Did you change vendors of your fans since I bought mine way back? The fan RPM's might be what is causing it to be objectionable to some. I have my 50 amp unit sitting on a cookie sheet in the area where I charge and discharge my Drone Batteries. I don't really need that much power for the batteries except when I am charging 5 batteries at a time. It is hard to believe that thing can fly with batteries that big and heavy.
     
  14. Megawatt

    Megawatt Contributing Site Sponsor

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    No vendor change, we just went to double ball bearing fans. The problem is if you reduce RPM you reduce CFM and cooling. To some its not loud if placed away from the radios and mics. To others its a jet engine. To me its not that loud as you can here four running in the 200 amp video. The server power supplies are about three times as loud. If anybody knows of a quieter fan???? Its really just the air blowing through the case that you here. We opened up the front of the case a few months ago, on our latest model, to let the air flow out with less restriction. That helped some.
     
  15. N0NB

    N0NB Active Member

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    Thanks, but I sold it on Monday and it went to USPS yesterday and is on its way to its new home.

    I keep it quiet enough in the shack that I can easily hear the hum of the RS-50M under the desk. I have it supported off the floor which reduced its noise considerably and I can still hear it quite well.

    If the fan in the Megawatt 50 had been under thermal control--as I incorrectly assumed it would be--it's quite likely I would still have it. But having that fan running full tilt even with no load was a deal breaker for me.
     

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