MegaWatt vs. Chinese Imitation 30 amp switching power supply comparison

[Singularity35]

What is up Exit 13. How you been? You would like the 50A model S-700-12, grab 2 or 3 and you can run some good power! Heck just 2 would suffice for a 4 pill. 4 would be very nice. They are honestly well made and the one I own has not failed me yet! It provides enough power to use my magnaforce 350hd with toshiba 2879's, and at 13.85vdc it shows right at 200w on SSB with the uniden 980 at 8-10w pep on SSB. Not bad at all. And no voltage drop either! I'm sure I could have used my optima mk3 and the magnaforce together on the same suppy (S-400-12), and still be able to use things fine. Due to the passing of the amp, or will take a bit of input, but 40w is about where I draw the line anymore. That shows 350-400 watts pep on SSB out of the amp. But at the cost of some heat! Not a bunch, but it gets warm. Pushing it with 20w pep it stays cool always. Anyways, like I posted before these PS units get from me. Have a good one.

How are 2 or more of them wired to get more amperage?

 

[Obed]

How are 2 or more of them wired to get more amperage?

watch the video posted above, or go to the website and watch it there... it shows exactly how they did it, and even gives recommended wire size...
simple answer, in parallel.

 

[Singularity35]

Thanks.

 

[ExitThirteen]

I plan on getting at least 3 of them. Will eventually get 4. I want 200A for the larger amps I repair. I might even run an Exitthirteen AB modified TS Sweet Sixteen for a base amp for those days I'm trying to check in on my local SSB nets and DX is bad.

~Cheers~

 

[WY7EM]

Ok, maybe I missed it... The S-700-12 is rated 50 continuous, is there a surge rating for it? I am looking to power a Tentec Hercules II with it and it will probably be close to the continuous rating.

I measured power consumption at max power on multiple bands at 49 amps, no guarantees that it won't draw a few amps more at some point though.

Tentec in their infinite wisdom published the power requirements at 100 Amps, apparently they were figuring in powering the rig off the same supply, with plenty of overhead.

 

[Megawatt]

Ok, maybe I missed it... The S-700-12 is rated 50 continuous, is there a surge rating for it? I am looking to power a Tentec Hercules II with it and it will probably be close to the continuous rating.

I measured power consumption at max power on multiple bands at 49 amps, no guarantees that it won't draw a few amps more at some point though.

Tentec in their infinite wisdom published the power requirements at 100 Amps, apparently they were figuring in powering the rig off the same supply, with plenty of overhead.

The S-700-12 will surge momentarily to two or three more amps but you never want to buy a 50 amp power supply for a 49 amp radio. Its kind of like buying a 150 pound rope to repel off a cliff with a body weight of 150 pounds. That's why the manufacturer is suggesting more amps. Its for over driving and over modulating the amp. Rule of thumb is radio or amp should draw 80% of the continuous output.

 

[Captain Kilowatt]

Ok, maybe I missed it... The S-700-12 is rated 50 continuous, is there a surge rating for it? I am looking to power a Tentec Hercules II with it and it will probably be close to the continuous rating.

I measured power consumption at max power on multiple bands at 49 amps, no guarantees that it won't draw a few amps more at some point though.

Tentec in their infinite wisdom published the power requirements at 100 Amps, apparently they were figuring in powering the rig off the same supply, with plenty of overhead.

Just wondering how you measured that and what meter you were using. It is quite possible that you were not seeing the true peak current unless you were running the amp flat out in a steady carrier mode since most meters respond to voice peaks too slow to be accurate. Just a thought as to why you were only seeing half of what Ten-Tec speced for current consumption.

 

[N0NB]

I just place my order for the S-700-12 based on this thread.

I'd been looking at switching power supplies when I saw the ad here and then this thread. So I'm going to take the plunge to replace my bulky and noisy Astron RM-50M.

 

[Megawatt]

I just place my order for the S-700-12 based on this thread.

I'd been looking at switching power supplies when I saw the ad here and then this thread. So I'm going to take the plunge to replace my bulky and noisy Astron RM-50M.

You will love it. If you have any problems or questions just let me know.
Thank you,
John

 

[Obed]

I think you will be pleased. I have 3 of them and think they are great.

 

[222DBFL]

My S400-12 is a workhorse for me! Has been flawless for about 3 years now. And yes I do use it quite often even if it's just to listen to the bands. The 50A supplies are great as you can parallel them without any other parts needed. Just adjust voltage accordingly. And the price is not bad at all for what you get!! Great CS, and a great PS as well!! Keep up the good work MegaWatt!!!!

 

[wavrider]

I purchased two of the 50 amp switching PS.
Running them in parallel and they work great.

I have some Chinese made 100vdc/100amp volt current meter with 100amp shunt that I use to monitor current and voltage. ( Ebay purchase)

I hear no hash on my HF rig on any HF band, nice quiet fans and superb performance.

Now in the words of "Paul Harvey, the rest of the story"

Shipping was fast, communications were way above average.
My PS arrived in my little town on the day the tracking said they were due to arrive..
Then due to a computer scanning glitch my PS got a week long tour of central Florida.
Megawatt power supply ( John ) kept in daily contact with me via email to update me on the where about of the PS and even when so far as to call the local postmaster in my small hometown.

Long story short customer service was provided way above and beyond expectations.Service after the sale was awesome.

A big THANK YOU to John for all the assistance in ensuring the PS were sent to the correct address.
I highly recommend the megawatt PS to any and all who are looking at a switching PS superior performance and awesome customer service.

 

[N0NB]

Well, this was not the review I planned to write when I ordered the MegaWatt S-700-12 last week.

In short, I am disappointed.

The package arrived on Friday February 3, and I was quite excited. I hooked the power cord to the supply and powered it up to set the output voltage. The fan ran up to full speed and remained there even though the supply was quite cold. After setting the voltage and waiting a bit, the fan never slowed down. It is LOUD!

I sent John an email as I was curious about this and in his reply he stated,

They are 60,000 hour rated double ball bearing fans. All switching power supplies rely heavly on fan cooling . We actualy have one of the quietest fans on the market for the power output at only 30db. We show that off on the video on the website with four of them running at the same time. Most people either move them to another room, farther away or put it in a sound absorbing box with vents.

My first thought was that this particular fan is much louder than 30 dB. Later that evening I remembered that I have a sound level app on my phone. Of course, the numbers could be off by several dB as I don't have an actual sound level meter to measure the acoustics.

Here is what I did measure and wrote in an email to John over the weekend that I've not received a reply to as of yet:

It occurred to me that I have an app on my phone to measure sound
levels. While the absolute levels may not be entirely accurate, I am
more interested in the relative levels.

First I measured the ambient sound level with the RM-50M on and all the
volumes turned down at about 32 dB.

Next, with the S-700-12 under the desk about where I would have it I
measured about 44 dB with it turned on from the same spot in the room.

Finally, with the phone about one meter away from the fan end of the
supply I measured about 54 dB.

By comparison, measuring my Ameritron ALS-600 amplifier which has fans
in the power supply that is located under the desk and the RF deck that
is on a shelf in the open above the desk it read 37 dB. I consider the
amp loud enough that I only use it when necessary.

I hope that helps explains my experience.

Other than hooking it up again to measure these levels, I've done nothing with the supply except put it back in the packaging.

If any one is interested, I would like to sell it. It is essentially new and has less than 5 minutes of on time in my shack.

 

[dave457]

Why not just install a fan to your liking, there cheap(money wise) and very easy to replace

 

[N0NB]

Can't do that without voiding the warranty as the covers have those labels at the corners stating as such.

In my opinion, the design should be such that the fan speed matches the cooling speed. Other switching power supplies I have seen have that capability and when the unit is supplying minimal or no power the fan doesn't run at all.

If the fan were off or running slowly most of the time, I most likely would have posted signing its praises. Running the fan at full speed with its attendant acoustic noise level all the time even when the supply is cold, is not what I expected after reading the comments here. It's also an unneeded and noisy distraction in my shack.