MegaWatt Switching power supply vs. Imitation Comparison
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- Опубліковано 17 бер 2015
- This video demonstrates the hash comparison of the MegaWatt 30 amp switching power supply with the Chinese copy. The difference between the two is amazing.
- Наука та технологія
I was doubtful of the Mega Watt claims.
I use a lot of switching power supplies 12 and 24 volt from 2 to 50 amps.
Most are used for building power supplies of old WW2 era military transmitters and receivers.
80% of the time,I cannot use them without adding Corcom style EMI filters and running all wiring through FT240-31 toroids
For powering up a new home brew project,an SDR transceiver and an Italian 200 watt MOSFET amp, I needed another lightweight switcher,as this rig will be traveling back and forth to Europe a lot.
I tried the 33 amp MegaWatt.
Amazingly quiet 80-10 meters without doing a thing to it!
I DID see two spikes of rf in the 160m band that I dont use .But they weren't that strong.
I imagine putting ferrite mix 31 chokes on the leads would eliminate those on 160m
In all,a very good investment in a well designed power supply!
Ron
NU6F
Get 2 0.1uf disc caps. One to the positive (+) terminal to chassis ground and one to the negative (-) terminal to chassis ground. That should fix the noise problem.
I actually reproduced the noise problem you demonstrated in your video, but only on the AM (broadcast radio) band. I didn't hear any of it on any amateur band using SSB. So, I can live without the AM band, and am very happy with this PSU for my amateur needs.
Bravo, good show. Very helpful.
You said it, traveling carrier. It does in fact travel on the Mega Watt just like on the cheap one. You need to change frequency on the radio and you'll find it. I added a capacitor to mine and can force it to move if it's in my way. Commercial supplies have a "Noise Offset" adjustment to move the noise. I'm getting ready to buy a cheaper one as a supply for other things. Note, the 120/240v switch on my Mega Watt burned out. I wasn't even using it and it had been sitting for a few moths. I turned the radio on and the radio had very low output and the signal was jumping around.
After a few minutes of checking the antenna connections etc, I pulled the Mega Watt apart and found the switch was loose and toasted, it had worked great before. I just soldered across the contacts and it'll never do that again. As I said, it worked perfectly and was not in use and went bad just sitting. I'm assuming the switch was loose to begin with and was burning as I used it previously. Other than that the Mega Watt is great but I have a feeling it's the same thing as the cheaper ones, if you get a good one with good parts. I'm sure some are made for maximum profit and not as good as others. As usual, look for good reviews.
Love my megawatt, and glad I spent the money on it. Their fans are quiet too.
thanks you just answered my question if $60 vs $24 was worth it.
yeah i have the MegaWatt s-350-12 i want to get 1 more and pare them up for 66amps they work GOOD!
Yeah, try it on 1930 kHz. Hash, traveling carrier, the works. After a while it clears up but until it does it's bad, really bad. Hashwise, tho, it is cleaner than a cheap chinese supply. On 160 I'd have S9 noise from the cheap 20A supply I was using, S3-S5 on the MegaWatt (after about 20 mins) and S3-S5 on a 12A JetStream (which also has the traveling carrier, but it moves much faster than the MW's).
I bought a cheap switching power supply and the noise was terrible. I returned it and bought the 50 amp Mega Watt switching power supply and it works great and is clean. Mega Watt is still made in China, just a good unit.
Yeah the Chinese are more than capable of producing the high quality products just like any country can, its up to the manufacturer to spend more money and not cut corners. The cheap junk that rolls out of Chine is because we are too cheap anymore as a Nation to spend money on quality
Cheap smps can work clean by applying 12V21W on 13.8 V lines. No hash no birdie at all
Greetings from Indonesia
I cant help but to wonder if a ferrite bead or two on the power wire would cut any of this
This is the trouble with cheap Chinese power supply's they leave out components to save money at the detriment of the end user .They do the same with computer supply's ,they leave out capacitors that should be filtering out the mains voltage and the result is what you are showing .I live in a built up are and there is a massive problem with power supply's radiating across the HF spectrum and our enforcers Ofcom will not do anything about it . I suppose the saying is right you get what you pay for!! Thanks for posting
I bought the s-400 PS and it blew my mind how small it is and how the Chinese one looks exactly like mine. The only difference I can see is the box it comes in. it would be interesting to see the inside of both supplies. I just wonder.
+eogg25 Here's a more detailed article with pics inside: www.worldwidedx.com/threads/megawatt-vs-chinese-imitation-30-amp-switching-power-supply-comparison.182976/#post-516753
Tim Tucker Thanks a lot, that is what I was looking for, So far it works good, but I'll wait a little while before I recommend it..
what computer prgram is that, that displays the signals??? how does one get that ?..ps great video!
Look into SDR usb dongles.
I only had one of these china replicas make noise in my receive, shortly after. It died, I think they are great for the money, people are burning up megawatt power supplies just the same, what makes theirs so much better anyways?
I wonder if one were to upgrade the caps in the china version if it would help the failure rate, I don't care for switxhing power zupploez they all seem to be made cheaply. Jist my two cents.
How does one get an 8 guage or larger power wire on those tiny posts?
Frederickdawg Offset connectors, or just Solder on the appropriate size ring terminal, and you're golden.
@@tsant6591 Panduit EV8-8R-Q fit 8 AWG wire, and fits the screw down slots perfectly. You can pull off the insulated part if need be, and insulate with what ever. I bought them from Digi-key.
www.digikey.com/product-detail/en/panduit-corp/EV8-8R-Q/298-16820-ND/9491379
wow glad i didnt go for the china copy!!
What kind of noise would it create if I were to have one to power my (150w 2 meter ssb) brick?? The Chinese one that is
+n0zqh It probably won't be as big of an issue on 2m SSB, but the supply still radiates noise while it's on. So if you have any HF gear around, it will drive you nuts. I tried powering a couple UHF radios with it, which worked fine, but my HF gear still picked it up, so I got rid of the supply.
+Tim Tucker Cool I will not to awfully afraid to pick one up.
People will actually tolerate this enough to run their radios with it? That's downright unuseable, at least it would be for me.
Use of misleading terms like "Chinese copy" does your review no favours. Not everything made in China is crap, most electronics are either made in China or the majority of their parts are made in China. Your beloved Mega Watt power supply is made in China, I know because I have one, love it, it just so happens to be built to eliminate the switch mode power supply noises. Take your average TV set from the old days when hams and CB'ers had to deal with TVI, why was there TVI, because the North American manufacturers refused to put 50 cents worth of filtering into their sets because it would put off consumers from buying their product. So, if you build to a higher spec, you get better results.
MegaWatt does have a trademark...so what? You mean some cheap, Chinese knock off can't fake a trademark? The real question is do you have a decent input filter, rectifier, heatsink, output filter, and decently large caps from reputable Japanese manufacturers? Let's see an inside view of a "real" MegaWatt vs the knockoff.
I have seen both its like night & day. All of those components you mentioned are all beefed up in the Megawatt supplies.
And while we're at it, does MegaWatt make these at some factory in the US or are they "imported" from some "reputable" Taiwan (Chinese) house? What if it blows up my rig? Oh, and those of you reviewing these on eHam, if you say "pill" I know you're a CB user, and not a Ham!
I could have done without seeing your toe nail.