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Reviews Categories | Power Supplies | MFJ-4245MV Help

Reviews Summary for MFJ-4245MV
MFJ-4245MV Reviews: 66 Average rating: 3.0/5 MSRP: $150-200.
Description: Switching and Non-Switching Power Supplies
Product is in production.
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NR7J Rating: 5/5 Apr 11, 2013 12:58 Send this review to a friend
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: 0/5 Feb 17, 2013 14:46 Send this review to a friend
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: 1/5 Feb 3, 2013 11:29 Send this review to a friend
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.

WP4OOI Rating: 0/5 Jan 23, 2013 17:28 Send this review to a friend
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: 5/5 Nov 8, 2012 13:57 Send this review to a friend
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: 0/5 Oct 19, 2012 04:17 Send this review to a friend
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.

KC5SAS Rating: 0/5 Oct 18, 2012 13:51 Send this review to a friend
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.
N5GOD Rating: 5/5 Sep 7, 2012 16:58 Send this review to a friend
No problems great power supply  Time owned: more than 12 months
I bought mine just after they came out from MFJ. I have had it for many years of trouble free service. Many of the reviews have trashed the PS because of fan noise or because the operator made a mistake. While the fan may make a little noise, it definitely is not unbearable. I have mine setting on the shelf above my radio. I would not hesitate to buy another one.
K4KDD Rating: 5/5 Jul 8, 2012 13:51 Send this review to a friend
Good power supply at a good price!  Time owned: 0 to 3 months
Read a lot of reviews about this power supply. Some good, some bad. Went ahead and drove over to MFJ and picked up this power supply. Works great! Fan noise is not that bad. Would recommend this for anyone that needs a good power supply. I bought it to replace a Samlex Sec 1235M power supply that I have had for a year.
KD8QDL Rating: 2/5 May 29, 2012 05:59 Send this review to a friend
Had to Repair  Time owned: 6 to 12 months
I also accidentally shorted out the DC on this unit. I sent it back and they either repaired it or just sent me another unit. The second one has very dim display meters (which are hard to read) and the voltage simply does not react well to the DC Adjust pot that controls it. It simply does not have the sensitivity or voltage potential of the original.

Additionally, in the repaired unit, the display lighting dims when the voltage pot is lowered and brightens when the voltage pot is raised (still unreadable at max voltage). This is unacceptable. The most I can get out of this unit is 14 volts which is fine as the most I should need is 13.8, but it simply is not the unit that I originally bought. I was very happy with the original, but the repaired unit is lacking in many areas.
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