MegaWatt S-400-12x 36 Amps 430 Watts 9.5 to 15 Volts Adjustable Ham CB Radio Power Supply 13.8V 12V Not a Clone - Real MegaWatt MW

This is a clean running power supply. Unfortunately it has become noisy from what sounds like the fan is touching something. Kinda like a scratching noise.

The media could not be loaded.  Updating this review. If the seller fixes the issue next summer, when I can return home to the USA for warranty work, I will raise this. I am raising it to 3 stars because the seller if a 5 in terms of initial service, but I'm just not impressed with the unit, given my experience with it.I have spoken with the seller. If you contact them, they WILL replace or repair units that are faulty or break down within the warranty period. If you check other websites, like eham, you will find several other buyers who can attest to their need for this, and that they were treated well.It's because I would not consider Amazon reviews of this unit as on the up-and-up. The seller WILL treat you well IF you agree not to damage his review status with a negative review. For that, you should feel confident that you will be taken care of. I had initially given this unit a 1-star review, but moved it up to three, because I believe the seller will replace your unit if it goes bad.However...I believe in a fair customer/seller review process, so I will be honest here. Upon finding my not-yet-updated 1-star review of this unit, I received an angry e-mail, stating that my unit would NO LONGER be replaced (so if you leave a less-than-stellar review, don't expect a replacement). After I asked if I was being blackmailed into leaving a positive review (and a few more snippy emails), I was gruffly told I would be required to submit it for warranty repair, instead -- followed by a list of required warranty service terms that seemed more like retribution and excuses they could make to not actually repair my unit, if they felt so inclined.So there it is. If you are surprised as to why these Megawatt units have such stellar reviews, you can read the above and come to your own conclusion.------------------------Here is my original review, which I didn't feel was too terrible:The unit died after three months. I hear a strange fan noise, and no power comes out. I have since moved to Korea, so I don't even know if it's possible, or worthwhile, to contact the seller about it. I was powering a Yaesu FT-950 HF radio. It worked fine until today (yes, I switched it to 220v three months ago). I always turned the unit off with power switch when not in use. It didn't quit working while in use. It simply did not work the next time I went to use it. Really disappointed.I found the reviews on eham to be more informational in terms of this unit. It seems you can get a replacement for your broken Megawatt quite quickly. A number of reviews on different sites seem to back this up. If you are like me, however, you'd rather not have to bother with sending these things back within a year, as many have done.After my Megawatt S-400 died, I did a little searching, and found this very informative information on eham, which might affect your decision as to whether you buy this, or how you use it:"One of my Mega-Watt S-400-12 supplies failed after about 18 months. I contacted the seller (still on eB**) who promptly replied, verified it had a 24 month warranty and invited me to send it in for repair. The supply was quickly replaced with a new one for $10 shipping cost. The new supply was installed, tested and ran great. I was told "the TL494 was damaged by a voltage spike". The TL494 is a 16 pin regulator IC that is apparently the heart of the power supply's control circuitry and not immune to AC line transients. I thought my station was immune to this because of installed surge suppressors but apparently not. The unit did not fail during use, it was dead when I turned it on to use it. So, from now on I will unplug it when not using it. Hope this helps someone else. I'm leaving 4 stars because it seems like in this day and age designers could have learned how to protect their A/C inputs from routine voltage spikes by wiring in MOV's or whatever they use for this issue."_______________________Now, for pure hypothesis on my part....In the end, I feel I might have been better off buying two of the half-priced Chinese units, which get 4-star reviews, for all practical purposes, seem identical to these in every way. I can't imagine they do much worse than dying within 3 months. Surely, one of the two would have lived.I also have a hard time believing that a 1-man shop manufactures and sells hundreds of these units on his own. I suspect what we have here is someone who sells the same thing at double the price, but what you are paying for is really great/fast return service, and a supposed longer warranty, if yours dies. He just slaps a megawatt label on it, then claims the others are a clone of his power supply. He can eat the cost of the returns, given the initial mark-up, and people who had one die (several on Eham, compared to here, where he dogged me for my negative review) are satisfied when he provides a quick exchange.I have no way of knowing if the above is true... just a theory.

This power supply powers a Kenwood mobile 50 Watt VHF/UHF radio nicely. The radio draws about 1 Amp on receive, and 13 Amps on transmit (set to the high setting). I previously owned a Chinese clone of this power supply that cost around $20, and it failed after about a year. After it failed, the inexpensive clone (rated at 30 Amps output) would suddenly would jump to 16 volts when the transmitter was keyed, and the radio attempted to draw 13 Amps to drive the transmitter. The radio has internal protection that limited the input voltage, so it protected itself, but many radios would have been 'fried' under this condition. The inexpensive power supply also generated some RF which got into the radio, as well. I am a retired electrical engineer, who did research and development on power supplies, so I know a bit about these things.This Megawatt S-400 is remarkably stable, and when set to 13.88V output at a 1 Amp load (it hold that voltage at no load as well), it will jump to 14.05 Volts when the load suddenly increases to 13 Amps (excellent voltage stability). No RF in the output, so it is a perfect power supply to use with a ham radio that requires a 12 Volt supply. Very stable, and very clean output. Voltage was measured with a laboratory Fluke voltmeter, with its calibration traceable to the NIST (used to be called the National Bureau of Standards). Its little fan runs slowly all the time, and it is reasonably quiet (much quieter than the fan on the Kenwood). If you value whatever you are powering with a 12 volt supply, do not buy the cheap Chinese clones, as you risk damaging some expensive equipment in the event of a power supply failure. This supply is relatively inexpensive compared to some of the 'name brand' supplies, and appears to be much better built than my previous, very inexpensive ($20) power supply.

Used this to charge my RV batteries. Works great! This is the second one I've bought. The first one I used on my Ham Radio and it has held up nicely.

I am powering two different 12V, 100W, Amateur radio HF / VHF / UHF transceivers with this.My previous power supply model was a 'cheap knock' off that claimed 30 amps, but burned out while I was drawing 15. On the 'cheap knock off', the lights on one of my panel meters would always flicker when I tuned 100 Watts (about 22 amps). This one is solid. Good clean power for a 12V radio.The output voltage is adjustable from about 12.1 to 15 volts. Mine came set to the lower output voltage of 12.1 and I easily set it to 13.6 (my preferred voltage).I keep learning this over and over, maybe some day it will stick, the cheap stuff isn't always cheap.This one is the real deal.KK6RBRI had to add this. On the 'cheap knock off' model that I had, the fan only came on sometimes but loudly. On this one the fan appears to be always on but at a very low level (no noise). Thank you for that. :) I used to sometimes get up in the night wondering where the noise was coming from.

Fast shipping! Received it 2 days after ordering, and from the opposite coast!Works as advertised. However a few things to be aware of:The fan noise, while not really loud, does continue constantly.As a switching power supply, in my case it creates a lot of noise in my HF transceiver, but only on 160m and 80m. Does not render them useless, but is a small annoyance. Several options to eliminate it and I'm working on them.That said, this power supply was a good purchase. My equipment uses a max of 22 amps, well within the specs for the PS of 36 amps. Would definitely do business with this company again!