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Reviews For: MFJ-4035MV

Category: Power Supplies

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Review Summary For : MFJ-4035MV
Reviews: 50MSRP: 150.
Description:
35 Amp Adjustable Power Supply
Product is in production
More Info: http://www.mfjenterprises.com/products.php?prodid=MFJ-4035
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
00503.4
KM4NYI Rating: 2018-10-21
Reasonably priced linear power supply Time Owned: 0 to 3 months.
I bought a 4035MV used at a Hamfest, and after some modifications, I think it's a good power supply.

Most reviews mention the loud fan, and they are certainly correct, the fan is unreasonably loud and obnoxious. A 50 ohm, 10 watt resistor in series with the positive fan motor wire brought down the speed just enough to make the fan nice and quiet, and everything still keeps cool. While I had it apart, I went ahead and touched up some of the solder joints that exhibited a little sloppy workmanship.

This power supply is actually a fairly well built model. Research shows this was made by Zurich for MFJ, which probably results in a better quality product than you typically get with MFJ. A massive heat sink with internal fins takes up the left side of the cabinet, with the bridge rectifiers and pass transistors mounted on it. The fan brings air in from a side vent where it passes over the internal heat sink fins and out the back of the cabinet. The power transformer looks to be very heavy-duty, and should have no problem keeping up with the 35 amp rating of the output. Voltage regulation is rock steady, and a quick peek of the waveform on a scope reveals a nice, pure DC output. Up-front meters for voltage and current are accurate, but are sadly not lighted.
Convenient features include a cigarette lighter plug, and a couple of 6 amp "quick connect" jacks for bench use.

Are there better built power supplies on the market? Sure. Can you buy a better 35 amp linear power supply for this price? Probably not. All in all, I think you get a lot of bang for your buck with this power supply.
K1TGF Rating: 2018-09-05
Good power supply. Time Owned: more than 12 months.
After having bad experiences with switching power supplies (noisy) I decided to try a linear. Despite the reviews of this supply I bought one. As other reviews have stated the fan is loud. The first two modifications I made to the supply was to add a quiet pc fan and a pc 3 prong plug so I could ground the supply to the mains and easily remove the cord for transportation. The quiet fan works well and I only notice it now when running digital modes due to the high duty cycle. I gave it 5 stars because for the money I feel it's a good supply. I've owned it for over 18 months with no serious issues.
KN6Q Rating: 2017-08-18
Good but it sounds like a jet fighter taking off Time Owned: 0 to 3 months.
I've purchased a new MFJ-4035MV (from Gigaparts) a little over two weeks ago.

I did this knowingly after seeing all the reviews with the fan being loud (on the MFJ product page it says "Whisper quiet fan speed increases as load current increases"). I was setting it next to my AL-811, which already had (what I considered) a loud fan, so I thought, how bad could it be? Maybe these other hams are overly sensitive?

When I first powered it on, I thought that it wasn't loud at all - then I keyed up my radio. It honesty startled me, and immediately un-keyed the mic.

It is loud. Orders of magnitude louder than my AL-811. I guess I've gotten used it now, so I'm not sure if/when I'm going to modify it (several suggestions in the reviews below).

Now - aside from that - it's an awesome power supply. You get all advantages of linear power supply, and it costs half the price of any of the others I saw. The cigarette lighter adapter is handy, I plug a USB charger into it.

It's a brick house that I expect to give me many years of service. It just sounds like a jet taking off when you key up.
KD2BOR Rating: 2017-01-24
VERY NOISY FAN OTHER WISE GOOD Time Owned: 0 to 3 months.
HERES WHAT I DID ORDERED FROM EBAY NUMBER 151880324711 LOW AMP FAN CONTROLLER WIRED 12 VOLT NG +POSS TO UNIT UNPLUGGED FAN FROM BOARD +HOOKUP TO UNIT DRILLED HOLE HAFT INCH FROM MFJ NAME MOUNT CONTROLLER-SET DIAL TO NINE OCLOCK ERERY THING QUIET +COOL-THIS WILL WORK ON ANY NOISY SUPPLY
VA1WAB Rating: 2016-04-16
Excellent value for the price 100% satisfied with this unit Time Owned: 0 to 3 months.
When I first considered the MFJ-4035MV and after I read the reports here on eHam Net and read all the complaints about the fan noise I decided not to buy it. However due to budget restraint(was purchasing a new transceiver also)I reconsidered. My research showed that the earlier units were built offshore, these later and present power supplies are being built in the USA.
1 The voltage adjustment does have a d-tent set at 13.8 so brushing against it does not change the voltage setting
2 The fan on mine is whisper quiet (can't hear it even on TX but a paper in front of the air outlet at the back shows that it is running). Two non important things to me, not a complaint (1) I would prefer the 35 amp outlet on the back of the unit. (2) although not necessary the meters could be lighted. I give it a 5 because it looks good, does the job and is quiet
KD6ET Rating: 2015-11-26
Add a pot to adjust fan noise Time Owned: more than 12 months.
I'll post pictures later. This is the safest amp for your expensive equipment. It has a massive old school transformer and crow bar safety circuit (rig will never see more than 18 V if regulator fails, not 120 V when a switcher fails) plus a state of the art massive V regulation circuit. The FAN NOISE was an oversight because they assumed it was to be an off bench unit at continuous 35 Amp. Not necessary when used as a ham station. I'll do some testing and find wich POT to install in the front panel to slow the fan when a continuous 35 Amp draw is not necessary (like in SSB or CW). The heat sink is also massive and I'll bet that on normal net use, the fan isn't even necessary.

----------------------
Earlier 5-star review posted by KD6ET on 2012-10-12

I bought this one because it had a full size transformer rated way beyond any demand I had. I don't understand why it's listed as a switching supply (type-o maybe?). I have a switcher rated at 30 amps and I think I hear some noise from it on receive but nothing using the 4035. It contains a full wave bridge rectifier and an 18 pound transformer followed by extensive regulation equipment. This one meets the old time standard for a quality DC supply I'm used to and glad to see this type is still available but, getting a little hard to find. It's weight is no problem since it will set on the table end or floor. I do not understand the fan noise comments. Unless mine is different, the only time I hear it is when the radio audio is turned all the way down, otherwise it's a lot quieter than the base level radio audio. I'm use to full limit linears and yes they're too noise for in-shack use on SSB. Mine goes up in the attic near the antenna.
WA7OPY Rating: 2014-12-23
junk Time Owned: 6 to 12 months.
Bought it new, then didnt use it until is was 12 mo old,My mistake. Fan runs full speed all the time, what a racket. Voltage was bounceing all over the meter until you hit it on the top. (Bad joints)Now it shuts down on OC at 5 amps. I just dont trust it to power a 2k trans. No help from mfj to old for free repair by 12 days and I would have to pay the shipping both ways 50$ I will use it for a batt charger. Real cheap parts inside with pp soldering. Will buy something else to replace it
AC5PS Rating: 2014-08-11
Worked great, lasted a long time. Time Owned: more than 12 months.
This is my review 16 years ago.

" I bought mine new in 1998 and has not given me any trouble at all. It gets used every day, it ran a repeater for about year, out side ! With it's different power hook-up's this power supply is very useful in the shack, yes the fan is a little noisy. I discovered something interesting, I noticed that the MFJ on the upper left side and the model number on the upper right side were stickers. When I removed them it showed " Zurich " and " DPS-3012M ". So this explains why it's still working !"

Today while using a TM-71A at 50 watts the transceiver was shutting down. The voltage meter was dropping to 9 volts. I connected the 71A to another PS and it worked fine. All and all can't complain after 16 years of daily use.
WB4M Rating: 2014-07-31
Noisy but does the job. Time Owned: more than 12 months.
I've owned mine for years, but haven't used it much. As others have mentioned, fan noise is unacceptable. The fan on mine comes on when you switch the power on, under zero load, and never stops until you turn it off. Too bad, otherwise it works fine, has 2 large meters, variable v. output, plenty of different types of connectors. I've never put it under a demanding load so can't comment about that. I really don't need it so think I'll just sell it, hi.
KQ4KK Rating: 2014-07-15
Good Value Time Owned: 0 to 3 months.
I've only been a HAM for 23 years. I've had two ASTRON RS-35M die, tho one of them died in a flood. So I bought a ALINCO DM-340MVT supply (big transformer). It lasted 7 years, till it took a lightning strike to the primary of the transformer. So I ordered another DM-340MVT. It overheated and died. Opened it up. The fan blade had come detached from the fan shroud and the fan was stuck in the wiring. Sent it back.

Got a MFJ-4035MV. Opened it up because it was a MFJ. It is made exactly like the ALINCO! But it is $30 cheaper, and no 3 prong plug.

The fan works too well. It is a little noisy. You start putting a load on it, it takes off like a C-130 FAN. And if you follow Bob Heil's "view" of grounding a shack, you don't want the supply grounded to the house wiring and noise.

Needs lighted meters.