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Reviews For: Mega-Watt S-350-12 Power Supply

Category: Power Supplies

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Review Summary For : Mega-Watt S-350-12 Power Supply
Reviews: 6MSRP: 50
An inexpensive switch-mode power supply rated at 30 amperes continuous load.
Product is in production
More Info:
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
WA1MAD Rating: 2016-10-02
Works GREAT! Time Owned: more than 12 months.
I use my Mega-Watt S350-12 almost every day and have done so for over a year. I had a few little questions and got almost "real time" responses from John. I detect no hf interference, voltage is super stable under load and it is audibly very quiet . I recommend it highly. Beware of inferior copies though. It performs as well or better as my switching Astron which I use when travelling or on my go box Yaesu setup.
NZ8I Rating: 2016-06-01
Cheap but they are trying. Time Owned: 0 to 3 months.
Well even after reading the reviews here I couldn't resist buying one of these "magic" power supplies...
Gotta say- delievered to my door for $58.00 USD is pretty amazin.
After smoke test -it works pretty reliably on all HF bands-except 160m.
160 is unuseable with this power supply. Noisy AC HUM from 1.8-2.0 with grounding having not any effect.

"Caveat Emptor"-think I'll stick wih the MFJ's easier to repair when new.

Keep trying "Mega-Watt" boys... You'll get there eventually...



EA3KS Rating: 2015-03-04
for compromise... Time Owned: 0 to 3 months.
Approximately 3 weeks ago I have bought this power supply. The manufacturer was indicating that it was filtered) to eliminate the possible noise in HF.I have bought this model, to restore my old woman Icom PS-30, it was damaged and was better to restore that to repair. And my surprise, it(he,she) is that once mounted, and connected to my TS-480SAT, I do the test of interference, and I see that there is noise in 18 MHz. 7 MHz. 3,5 MHz and 1,8Mhz, noise sign S-5/6 on s-meter.
The Radio and Power-Supply are connected to ground independently.
Solutions: I install ferrita in all outs of 13.8v, and And I do not obtain anything, in the moment that I have placed 2 ceramic condensers in parallel of Negative pole to ground, it has eliminated all the interferences and noise, Except in 160m, it is a band that I do not use, but probably changing the values of the condensers could eliminate, (To later)
The speed of the internal FAN, it does not change, always this one connected and to the same speed.
See the result in my WEB

I think that it is a Power Supply of compromise, better an Astron!!

73 Joe EA3KS ( sorry for my English)
KC9VZB Rating: 2014-02-04
grrrrreat! Time Owned: more than 12 months.
I never have extra money .Bought this over a year ago and haven't found any rf noise.while it was powering my radio I had a brain fart and went to cut a second cord(while hot) spliced in to test a mobile rig to change plug.Volume dropped out on playing radio,power supply groaned and when I let go of dikes all was well.Very impressed! usually this leads to letting out the magic smoke,which happened to the one I was home brewing before it was finished
K3NB Rating: 2013-11-23
Works. Good price point. Time Owned: 0 to 3 months.
If you're new to this hobby and don't want to put out several Benjamins - or more -for a 30+ amp switching for a linear power supply in the same range, this might be just the thing you're looking for. It was for me anyway. I already had an Astron RS 30M and was marveling at how much heat it put out. Between it and my Ameritron AL811H I think I can leave the small space heater off this winter in my basement "shack." So I was looking at switching PSs and saw this one listed on eBay for about a third of what I paid for the other PS and thought for the money, it might be a good backup. You read all over the place about people's negative experiences with every power supply no matter the manufacturer. Even Kenwood, as good a reputation as they have, seemed to "forget" to put a crowbar over voltage protection circuit in their boat anchor PS-50 line years back and are now asking over $400 for the new updated model with protection (what a racket... protection? a pun... never mind). So with all this in mind I thought I'd go ahead and spend the $60 for one of these PSs - not knowing later that they're generally available for less elsewhere. I mounted a 1" digital volt-meter - Radio City - atop the PS and have been running my Kenwood TS-590S and several outboard chargers and meters through a Rigrunner panel for several weeks now. Volt meter shows a stead 13.8V with a rare flicker to 13.7 and the fan is steady, audible, but the sound pressure level is well under 40 dBA as measured 24" away, my sound level meter doesn't have a lower range than 40 dB so I can't tell what the sound pressure is at my ears, but I CAN hear it running, steadily. For comparison, the volume from my radio is over 50 dBA. As far as radio noise is concerned, from 6 to 160M I can't detect any more than was there before. Running this PS my shack's a little colder - as it gets colder outside - so I may go back to my Astron foot warmer shortly. I'm thinking about gutting my - broken - Kenwood PS-50 and putting this switching PS inside it, upgrading the back panel to Anderson Power poles. Recycling the copper in the transformer may pay for the switching PS ; - ).

I think, for the money, for the form-factor, I'd give it a 5. For the fan noise and the simple to shock yourself if you're not paying attention screw-down power strip in back - Weco style blind entry screw connectors would be safer, not necessarily more secure - and lack of an easy means of accessing or seeing the "power on" LED I'd give it a 4. This unit needs to be put into a larger box with more conveniently-accessible controls, connections, and indicators. I'm going to look around for a digital ammeter for it.

My rating, combined with the previous review, a 4.5 is about right. You could do worse.
WB6FLY Rating: 2013-05-19
Very Good Value Time Owned: 0 to 3 months.
I bought this power supply to see if it was as good as many others say it is. It seems to be a copy of the Mean Well S-350-12, but the specs are slightly different. I ran a full bench test and found that it performed well. Even after six hours of feeding a 30-ampere load at 13.8 VDC, it never faltered. The fan runs continuously at one speed, and does not appear to be thermostatically controlled as the instruction sheet states. I gave it a 4 only because the fan has sleeve bearings and may not survive years of operation with the axis vertical. I prefer ball bearings. My full test report is on the Repeater-Builder site.