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Reviews For: MFJ-4245MV

Category: Power Supplies

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Review Summary For : MFJ-4245MV
Reviews: 73MSRP: 150-200.
Description:
Switching and Non-Switching Power Supplies
Product is in production
More Info: http://www.mfjenterprises.com/products.php?prodid=MFJ-4245MV
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
00733
VK6SMK Rating: 2013-10-30
Overvoltage at output Time Owned: 3 to 6 months.
It is only when it happens to you that you look to see what others have experienced.
I wish I had read reviews before now.
I have seen the video clip on the net and read whats on here.
I had the exact same thing happen to me a few days ago. The PSU went into overvoltage at the output around 34V. It blew up my Yaesu radio's protection diode, thankfully it was in the circuit. The radio was not even on. It also damaged other equipment. The agent in the USA has been very helpful. For a few dollars fitting similar protection in the Yaesu circuit would be a good idea. Not very happy with this at all.
AE8MM Rating: 2013-10-20
Dead out of the box... Time Owned: 0 to 3 months.
I've had good luck with previous MFJ products and didn't buy into the negativity that is usually attached to the products they make.

My luck ran out with this power supply.

Out of the box, poor workmanship could be seen. There were several wires pinched between the front cover and the case.

Not seeing any other obvious defects, I put a Yaesu 2800M onto it and plugged it in. Nothing...

No lights, No volts, no nothing. Checked the fuse and it was good. At this point rather then trouble shoot it, I elected to just return the product.

Here's the fun part.

So I was going to just exchange the supply for another. The salesman wanted to check the returned supply first. He plugs it in and BAM!, sparks everywhere.

At that point I decided I was going to exchange for something other then a MFJ supply.
W4KHZ Rating: 2013-06-21
Waiting for repair from MFJ X 2 Time Owned: 6 to 12 months.
DON'T BUY IT. I am waiting for it to return from MFJ for the second time. First time it took out 2 transceivers that cost some serious money to repair,not to mention that I have paid the shipping to and from MFJ twice. Same problem that most have experienced. NO PROTECTION !
When I talked to MFJ they said they would fix their product but no help paying for the radios that were damaged.I've had this P.S. for 11 months. When it comes back I'm getting rid of it, Only 1 month left on warranty...Fan noise not a problem for me, P.S. is under the bench.
NR7J Rating: 2013-04-11
Not sure now. Time Owned: more than 12 months.
So far my MFJ-4245MV is working fine but after reading all the negative comments I don't keep it connected to any radios anymore. Fan noise not too bad.

MFJ says "Fully Protected
You wont burn up our power supplies! They are fully protected with Over Voltage and Over Current protection circuits."

Maybe what they mean is that the POWER SUPPLY is protected and you won't burn it up but according to the negative comments good luck with your rigs.
K4JAH Rating: 2013-02-17
What a shame. and disssapointment Time Owned: 6 to 12 months.
Turned it on and pop, smoke and meter stuck all the way to the left. Walked out to the trash bin and tossed in. I have one more to go but replaceing it with the qje 50 amp before it's to late. I now have one of the qje and it seems fine. Just ordered the second one. BEWARE BOYS AND GIRLS.
K6ZRH Rating: 2013-02-03
False Advertising Time Owned: 6 to 12 months.
MFJ-4245 is falsely advertising that this power supply has an overvoltage protection per specs. I burned my HF because of this issue. Some strand of wire shorted the output terminal for 2 seconds and the power supply is runs crazy about 35 volts! My IC-735 is now fried. MFJ replaces my power supply but not my HF. If you examine their circuit, it doesn't have a crowbar circuit compare to my old Astron that doesn't have an issue for 17 years! Don't buy this crappie experimental product of MFJ.
I like some of their products, but not this one, it is poorly engineered.

K6ZRH

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Earlier 1-star review posted by K6ZRH on 2012-05-21

I had my MFJ-4245, 45 Amps switching power supply about a month, "no hash" feature is ok. lighter weight is also good, but I accidentally shorted the DC output with few strands. The power supply fuse had blown, and replace it with internal spare fuse. When I turned-on the main switch, the power supply went crazy, output voltage went crazy up to 30 volts!
That means, there's "NO Short Circuit Protection and NO Over voltage Protection."
This power supply almost damage my TS-480HX!
I still settle for my old ASTRON, 10 years of use and too many accidental short circuit, it will just reset automatically without a problem.

Poor design, MADE IN CHINA
WP4OOI Rating: 2013-01-23
Overvoltage Time Owned: 0 to 3 months.
"Over Voltage and Over Current protection" it can't take a short at the output. If you touch the output leads together, your 13 volt supply suddenly puts out 33 volts. No protection :-(
AC6DX Rating: 2012-11-08
Never a Problem had since they first came out Time Owned: more than 12 months.
5 of 5 Never a problem, powered up my 746-PRO for Years, Yes it has a Fan NO IT IS NOT LOUD AT ALL, I have to be the luckiest Ham around never an issue with mine, I do not understand all the fuss about Fan Noise or at least my Fan is Whisper Quite as Advertised. Too Many Only taking the time to wright a review if they have a problem.
NO PROBLEMS HERE. WOULD BUY ANOTHER IN A FLASH WITHOUT HESITATION, but then again Mine still keeps plugging along.
KC2YXU Rating: 2012-10-19
Also had overvoltage Time Owned: more than 12 months.
I have had my MFJ-4245 power supply for about 2 years. A few weeks ago, I was using the power supply to test a small ac inverter that had a power draw of about 10 amps. After about 5 minutes runnimg the inverter with a 100 watt load, there was a small "Pop" and the voltage needle pegged over 16 volts. I shut the power supply off as fast as I could, but the inverter was still destroyed. I was lucky that my TS-440, which I usually power with this supply, was disconnected.

When I measured the output of the power supply, it was at about 33 volts. Upon further inspection, I foun a shorted 1n4148 diode that seemed to be just tacked onto the pcb. After replacing the diode and a blown resistor, the power supply works again, but I don't trust it anymore, and I can't in good concence sell it.

Ian
KC2YXU
KC5SAS Rating: 2012-10-18
over voltage fried a radio Time Owned: 0 to 3 months.
I bought this Like New In Box from a ham in my local club ($135). He had purchased it new at a HamFest from a dealer. I've had it on my desk for a couple of weeks hooked to a Yaesu 8500 dualband mobile and a Yaesu FT-100D. Today I was QSOing on the local repeaters on the Ft-8500 when I decided to turn on the Ft-100D for some HF monitoring. I pushed the power button on the 100D. Suddenly there was Popping and sparks from the back of my desk. The wire connections were zapping. I shut off the power supply but not before the 8500 went dark. The VOLTAGE needle on the power supply was pegged way past 16V. I disconnected everything and turned it back on. The fans were going so fast I thought it was going to take off like an airplane. Turning the DC Adjust does nothing. I've used another power supply to power up the 100D and it seems OK but the 8500 is not coming back on. Fuses look good but the radio is off. Trying MFJ tech support but the phone is busy. This sucks.