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MegaWatt vs. Chinese Imitation 30 amp switching power supply comparison

That's cool. The reason they last so long is that they don't heat cycle and brake parts like the cheap ones. Also there are parts that increase life like the huge inrush currant suppression thermistor that becomes 200C 3 seconds after you turn it on. They are a different animal.
 
I've had my S-400-12 supply since March when I got my TS-450SAT. Yes, it was overkill, but I figured I'd better leave some room to grow. I'd just gotten my license in January, and was told this hobby apparently has a way of breeding radios when you're not looking. (Sure enough, there's a TM-721A now setting on top of the HF rig.)

While the small fan inside isn't noisy by some comparisons, I, too, wished it was quieter. Rather than build a box, I exchanged emails with John asking about CFM requirements, etc. for a fan swap, and received a quick reply each time... and on a Sunday, no less. Fast forward to today. I had another (final) question about current draw on the fan circuit, got another almost immediate reply from John (OK, it took a whole six minutes), and proceeded to complete my "bigger fan, lower speed, more airflow" installation. Now the fan is virtually silent, and cooling will be as good or better than with the OEM one.

IMG_20180928_160122256~01.jpg


Kudos and thanks to John and MegaWatt for building a quality, US-made product at an affordable price, backed with great customer service and support.

KE0PSJ
 
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My S-400 arrived yesterday...fast shipping from CA to NC. Nice looking little PS. Only thing I've done with it is attach power cord, plug it in and turn it on.

Fan runs quiet to my ears and moves some air...nice breeze! I'll hook it up to a radio someday.

http://www.megawattpowersupplies.com

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Is there anything that can be done about an S-700-12 that has a little hash on 20 and 40 meters? I added some bigger fans to quiet it down a little, and was a little disappointed with how hyped up these are.
 
Is there anything that can be done about an S-700-12 that has a little hash on 20 and 40 meters? I added some bigger fans to quiet it down a little, and was a little disappointed with how hyped up these are.

Try calling John up and tell him what you're seeing. Maybe you got a bad one. Or maybe your experience can help product improvements.
 

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