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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
N5GOD Rating: 2012-09-07
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: 2012-07-08
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: 2012-05-29
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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Earlier 5-star review posted by KD8QDL on 2011-08-24

I have had nothing but good luck with my MFJ-4245MV. The fans are simply not very loud at all. The unit I am using has the fan speed directly controlled by the voltage control knob. Therefore it is silent at low voltages and virtually silent at higher voltages. Fan noise is not an issue at all as I am powering a Yaesu-FT 900 and a Yaesu FT-1900, both at 13.8 volts. This unit has more than enough power to run my equipment, and I am happy with what I consider to be a non issue concerning fan noise. Others may disagree, but the new unit I have is effective, efficient, and more than quiet enough for my money. I would buy another without reservation.
K8BMA Rating: 2012-05-28
FAN NOISE!!! Time Owned: 0 to 3 months.
Bought MFJ4245MV to power an AT-450 I recently acquired. Imagine my surprise when I fired up the power supply and the fan noise was louder than the rig and everything else in the shack. A review of the schematic shows the fan connected across the output. Run the supply at 13.8V and the fan runs at full speed. Further review shows that the supply is powered by switching regulator control chip that's been around for 25 years. For $150 for a supply, I would have expected a temperature controlled fan. Wish I had read these reviews sooner!
N3WOH Rating: 2012-03-09
Excellent product,great price. Time Owned: more than 12 months.
I bought this power supply in 1995 when I received my first amateur radio license. It is in use every day since I do not own any other. There was never any reason to repair or service this device. It has worked without failure from the day that it was purchased. The MFJ-4245MV powers all my QRP and QRO equipment. Thank you MFJ for providing such a well made product. Richard, N3WOH

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Earlier 5-star review posted by N3WOH on 2012-03-09

I bought this power supply in 1995 when I received my first amateur radio license. It is in use every day since I do not own any other. There was never any reason to repair or service this device. It has worked without failure from the day that it was purchased. The MFJ-4245MV powers all my QRP and QRO equipment. Thank you for providing such a well made product. Richard, N3WOH
WA6NAB Rating: 2012-02-16
Warning on early failure of P/S Time Owned: 3 to 6 months.
First unit failed in overvoltage condition about the 4th or 5th time I turned it on. Had it connected to my NEW FT950, so the transceiver was damaged. The seller replaced the power supply immediately, but told me I had to work through Yaesu to get the transceiver repaired. $50 shipping later I had the FT950 off to southern California for warranty repair (no charge to me except the shipping to them - I didn't explain anything except that the display was blank). Apparently only the module containing the display power supply was damaged. All is working well now, but I keep the power supply isolated until it is on and working correctly (power switch on the power distribution box). Won't buy another one. One other point - fan noise is not a problem.
AJ0Z Rating: 2012-01-17
Fan is Quiet Time Owned: 0 to 3 months.
Just received this unit today. So far after several hours running my HF station the fan is totally silent at 3 ft away from unit in my operating position. If I put my head right near the unit I can here the fan run. and the run lamp is lit. I'll follow up after using it for a while
W7MAG Rating: 2012-01-08
LOUD but works. Time Owned: more than 12 months.
Works fine for me as a power supply.
In a remote radio.
Located in a garage.

If I had to sit next to this thing in my quiet shack, well,... I wouldn't.

Pros:
Supplies power as I need it.
Fairly cheap.
Nice meters.
Been reliable for many years.

Cons:
Really loud fans. Almost hair dryer-ish..
(Sounds like an RB-211 spooling up.)

Would I recommend to a friend?
As a remote base supply? Sure.
As a primary Shack supply?
Unless located in another room, no.
KD5UTC Rating: 2010-07-30
MFJ CRAP Time Owned: 6 to 12 months.
i have tried twice to post review of this power supply on mfj site they will not post it .well here you can get the truth about there junk .The first one i purchased from them it burned up my 2m Rig volt went threw roof and they wouldnt replace my rig then they sent me my second one after i had to pay shipping both ways the second one ....the second one wont even hold current for a little 100w 2m amp it keeps throwing over current protection alert ..What is up with that BUY BEWARE OF MFJ POWER SUPPLY!!!!!
W9SAS Rating: 2010-07-03
Got earplugs? Time Owned: more than 12 months.
I bought one of these supplies (used) to use with battery chargers for electric R/C model boats. I was aware of the loud fan reports but didn't care since I was using it mostly outdoors. Recently I swapped some gear around and now I'm using it to power my HF rig. The power supply is fine, except that the fan noise is unbearable. Perhaps the fans in my unit were worn when I got it, but with the power supply in a closet six feet away and the door closed, fan noise is still getting into my TX audio.

I considered simply slowing down the fans with a dropping resistor, but decided against it. The schematic on the MFJ website shows a single fan but my unit has two, so MFJ must have encountered enough failures to add a second fan at some point. When they did, I'm sure they went with the cheapest fans possible. When I disassembled my unit, I found the outward-blowing fan was rated 34 cfm @ 35 dBa, while the internal fan was 16 cfm @ 32 dBa! That's pretty noisy, even for generic computer case fans.

My solution was to order two Silenx 80mm 32 cfm @ 14 dBa fans from Newegg.com, and I'll install those when they show up. They were 14 USD each, so this was not a cheap fix. Hopefully they'll provide enough ventilation while curing the noise problem- for awhile. But fans don't last forever, and they get noisier as they wear out. We'll see how long they last. At least I'll have quiet audio in the meantime.