Manager - NA4M
Manager Notes

Reviews For: MFJ-4103

Category: Power Supplies

eMail Subscription

Registered users are allowed to subscribe to specific review topics and receive eMail notifications when new reviews are posted.
Review Summary For : MFJ-4103
Reviews: 9MSRP: 39.95
Small, laptop PC style (albeit smaller) switching supply. Comes with adapter cable for FT 817. 1.5"X2.5"X4" Weighs 10 ounces
Product is in production
More Info: http://
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
K4TB Rating: 2017-09-20
Noise Generator Time Owned: 0 to 3 months.
I ordered the MFJ-4103 power supply which was specifically advertised for the FT-817 transceiver. It produced a lot of hash and interference in the radio, so I returned it. I should have read the reviews first. Then I ordered MFJ-1317 and found it to be a perfect fit - no hash or interference in my FT-817 and a slight bit smaller and lighter. It had the same output: 2.89 amps at 13.9 VDC, and was $15 less in price! I don't understand why MFJ created the MFJ-4103.
AI4QT Rating: 2007-11-23
No problem Time Owned: 0 to 3 months.
So far, so good. I haven't had any problems with noise. I was hesitant to puchase this item because of all the negative comments on the post... but so far I'm pleased with the unit. The only negative is the price... seems a little steep.
WH6JP Rating: 2007-07-17
better choice for ft-817 ? Time Owned: 0 to 3 months.
I don't have one, my friend let me use his
ft-817nd with the mfj-4103, small yes...
hash yes. So what is a better choice ?
KE2SP Rating: 2004-05-27
Noise-Plus Time Owned: 3 to 6 months.
I purchased one of these for use with my FT-817. I like the size and the fact that it operates on 110 and 220 V, since I operate in the USA and Europe. Unfortunately, the unit I received had a typical hash/spurious level of S5 or more every 100 Khz across the HF bands. I contacted MFJ and they agreed to exchange it. The new unit I received was even worse, with an S8/9 spurious level! Since I was leaving for SV8/land I had to take it. But what a nuisance. The spurii would drift in frequency and annoy QSO's and even the strong BBC news broadcasts. I just got back to the USA and contacted MFJ again, and they basically said 'tough luck'. Thanks loads guys. Next time I have a problem like this I will just return it for a refund. About the only thing its good for is a VHF/UHF rig.
WR2W Rating: 2004-03-20
AWFUL Time Owned: 0 to 3 months.
I can understand hash with switching supplies but this one is Awful! I like to buy & try but I would not post this one for sale. Period.
K6FYY Rating: 2004-02-12
Portable Noise Generator Time Owned: 0 to 3 months.
I'm on my second unit. First one was putting out all kinds of hash from 10 MHz down. This replacement unit knocks out the high end of 17meters and the HFPack calling freq. Perfect!

Good small supply, seemed to make a lot of sense. But you have to tune around all the garbage this thing radiates. Even if it's not connected to the 817, you have to disconnect the power from the supply itself to really gauge the effect on the noise floor. (Goes from S8 to nil on 17meters.)

Sorry, but I really can't recommend this power supply.

KG8ZH Rating: 2003-02-07
Works Great Time Owned: 6 to 12 months.
I have heard many people say this supply generates a lot of hash. Well I must be one of the lucky ones that got a good one because my supply don't generate any hash at all. The supply is very compact and fits nicely in a suitcase with my 817. I also use it to power mt HT too.

Chuck KG8ZH
N3EQJ Rating: 2002-06-18
excessive noise Time Owned: 0 to 3 months.
marked noise and static from the unit even when it is not actually connected to the 12v input of the 817; we tried one from AES and sent it back to try a second one-same problem; AES as always-no problem with them and the return/refund; but this unit clearly has a filtering and/or shielding problem; an S 7-9 noise level is unacceptable, especially if working weak signal QRP stations; MFJ needs to revisit this one
K8DXX Rating: 2002-02-08
Lots 'O Hash Time Owned: 0 to 3 months.
Just took delivery from Universal Radio (good price, $36.95). Powers my FT 817 at 14.2 volts (higher than expected but OK, I guess) well, as long as the receiving antenna is 70 feet away (like, radio, PS and I are in the basement ham shack and antenna is on the tower). In portable situations (MP1 antenna within 25 feet) this MFJ supply raises noise from S-0 to S-7 as soon as its plugged in. Connecting it to the radio makes little difference (must be radiating from the case).

I have added large ferrite split beads on the AC line cord and at both ends of the DC cord. This lowers hash to S-5 but gives it a 'rougher' sound.

Talked to a tech. at MFJ who had never heard of the problem before. Don't know whether I'm going to send it into MFJ for repair or back to Universal for a refund.